CS0-003 Questions and Answers

Reverse engineering is a technique that involves analyzing a binary file to understand its structure, functionality, and behavior. Reverse engineering can help security analysts perform malware analysis, vulnerability research, exploit development, and software debugging. Reverse engineering can be done using various tools, such as disassemblers, debuggers, decompilers, and hex editors.

Deploying an additional layer of access controls to verify authorized individuals is the best compensating control for the authentication vulnerability that could bypass the primary control. A compensating control is a security measure that is implemented to mitigate the risk of a vulnerability ora threat when the primary control is not sufficient or feasible. A compensating control should provide a similar or greater level of protection as the primary control, and should be closely related to the vulnerability or the threat it is addressing1. In this case, the primary control is to restrict access to a sensitive database, and the vulnerability is an authentication bypass. Therefore, the best compensating control is to deploy an additional layer of access controls, such as multifactor authentication, role-based access control, or encryption, to verify the identity and the authorization of the individuals who are accessing the database. This way, the compensating control can prevent unauthorized access to the database, even if the primary control is bypassed23. Running regular penetration tests, conducting regular security awareness training, and implementing intrusion detection software are all good security practices, but they are not compensating controls for the authentication vulnerability, as they do not provide a similar or greater level of protection as the primary control, and they are not closely related to the vulnerability or the threat they are addressing. References: Compensating Controls: An Impermanent Solution to an IT … - Tripwire, What is Multifactor Authentication (MFA)? | Duo Security, Role-Based Access Control (RBAC) and Role-Based Security, [What is a Penetration Test and How Does It Work?]

The correct answer is A. 121.19.30.221.

Based on the log files and the organization’s priorities, the host that warrants additional investigation is 121.19.30.221, because it is the only host that accessed a file containing sensitive data and is not from the partner vendor’s range.

The log files show the following information:

The IP addresses of the hosts that accessed the web server

The date and time of the access

The file path of the requested resource

The number of bytes transferred

The organization’s priorities are:

Unauthorized data disclosure is more critical than denial of service attempts

Denial of service attempts are more important than ensuring vendor data access

According to these priorities, the most serious threat to the organization is unauthorized data disclosure, which occurs when sensitive, protected, or confidential data is copied, transmitted, viewed, stolen, altered, or used by an individual unauthorized to do so123. Therefore, the host that accessed a file containing sensitive data and is not from the partner vendor’s range poses the highest risk to the organization.

The file that contains sensitive data is /reports/2023/financials.pdf, as indicated by its name and path. This file was accessed by two hosts: 121.19.30.221 and 216.122.5.5. However, only 121.19.30.221 is not from the partner vendor’s range, which is 216.122.5.x. Therefore, 121.19.30.221 is a potential unauthorized data disclosure threat and warrants additional investigation.

The other hosts do not warrant additional investigation based on the log files and the organization’s priorities.

Host 134.17.188.5 accessed /index.html multiple times in a short period of time, which could indicate a denial of service attempt by flooding the web server with requests45. However, denial of service attempts are less critical than unauthorized data disclosure according to the organization’s priorities, and there is no evidence that this host succeeded in disrupting the web server’s normal operations.

Host 202.180.1582 accessed /images/logo.png once, which does not indicate any malicious activity or threat to the organization.

Host 216.122.5.5 accessed /reports/2023/financials.pdf once, which could indicate unauthorized data disclosure if it was not authorized to do so. However, this host is from the partner vendor’s range, which is required to have access to monthly reports and is the only external vendor with authorized access according to the organization’s requirements.

Therefore, based on the log files and the organization’s priorities, host 121.19.30.221 warrants additional investigation as it poses the highest risk of unauthorized data disclosure to the organization.

A mean time to remediate (MTTR) is a metric that measures how long it takes to fix a vulnerability after it is discovered. A MTTR of 30 days would best protect the organization from the new attacks that are exploited 45 days after a patch is released, as it would ensure that the vulnerabilities are fixed before they are exploited

SLA (Service Level Agreement) is the best term to describe the document that defines the expectation to network customers that patching will only occur between 2:00 a.m. and 4:00 a.m., as it reflects the agreement between a service provider and a customer that specifies the services, quality, availability, and responsibilities that are agreed upon. An SLA is a common type of document that is used in various industries and contexts, such as IT, telecom, cloud computing, or outsourcing. An SLA typically includes metrics and indicators to measure the performance and quality of the service, such as uptime, response time, or resolution time. An SLA also defines the consequences or remedies for any breaches or failures of the service, such as penalties, refunds, or credits. An SLA can help to manage customer expectations, formalize communication, improve productivity, and strengthen relationships. The other terms are not as accurate as SLA, as they describe different types of documents or concepts. LOI (Letter of Intent) is a document that outlines the main terms and conditions of a proposed agreement between two or more parties, before a formal contract is signed. An LOI is usually non-binding and expresses the intention or interest of the parties to enter into a future agreement. An LOI can help to clarify the key points of a deal, facilitate negotiations, or demonstrate commitment. MOU (Memorandum of Understanding) is a document that describes a mutual agreement or cooperation between two or more parties, without creating any legal obligations or commitments. An MOU is usually more formal than an LOI, but less formal than a contract. An MOU can help to establish a common ground, define roles and responsibilities, or outline expectations and goals. KPI (Key Performance Indicator) is a concept that refers to a measurable value that demonstrates how effectively an organization or individual is achieving its key objectives or goals. A KPI is usually quantifiable andspecific, such as revenue growth, customer satisfaction, or employee retention. A KPI can help to track progress, evaluate performance, or identify areas for improvement.

Comprehensive and Detailed Explanation From Exact Extract:

To detect outdated software packages (installed software versions, patch levels, missing updates) on a server, the most effective methodology is credentialed scanning, because it allows the scanner to log in and inspect the system “from the inside,” including installed versions and patch status.

Exact extract (Sybex CySA+ Study Guide):

“Administrators can provide the scanner with credentials that allow the scanner to connect to the target server and retrieve configuration information… For example, if a vulnerability scan detects a potential issue that can be corrected by an operating system update, the credentialed scan can check whether the update is installed on the system before reporting a vulnerability.”

Exact extract (Secbay Press):

“With privileged credentials… the vulnerability report will be able to identify settings like these: Installed software version… Patch levels …”

Why the other options are not correct:

A (DLP) is for preventing sensitive data leakage, not detecting outdated packages.

B (Configuration management) helps maintain desired state, but the question asks specifically for a methodology to detect outdated packages—credentialed scans directly enumerate versions/patch levels.

C (CVE) is a naming/cataloging system for known vulnerabilities; it doesn’t, by itself, detect what’s installed on your server.

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Reverse engineering is the process of analyzing a binary file to understand its structure, functionality, and behavior. It can help to identify the purpose of the binary file, such as whether it is a malicious program, a legitimate application, or a library. Reverse engineering can involve various techniques, such as disassembling, decompiling, debugging, or extracting strings or resources from the binary file123. Reverse engineering can also help to find vulnerabilities, backdoors, or hidden features in the binary file

AUSB drop attackis acommon method for delivering ransomware, where an attacker leaves infected USB drives in strategic locations,tricking employees into plugging them into corporate devices​.

Option B (LFI - Local File Inclusion)exploitsweb applications, but the scenario lacksnetwork intrusion indicators.

Option C (Cross-site request forgery - CSRF)is used forexploiting authenticated web sessions, not ransomware delivery.

Option D (SQL injection)is used fordatabase exploitation, not file encryption malware.

Thus,A (USB drop) is the correct answer, asphysical malware introduction is a known ransomware attack vector​.

The correct answer is C. Legal department.

According to the CompTIA Cybersecurity Analyst (CySA+) certification exam objectives, one of the tasks for a security analyst is to “report and escalate security incidents to appropriate stakeholders and authorities” 1. This includes reporting any inappropriate use of resources, such as installing cryptominers on workstations, which may violate the company’s policies and cause financial and reputational damage. The legal department is the most appropriate group to escalate this issue to first, as they can advise on the legal implications and actions that can be taken against the employee. The legal department can also coordinate with other groups, such as law enforcement, help desk, or board members, as needed. The other options are not the best choices to escalate the issue to first, as they may not have the authority or expertise to handle the situation properly.

ABusiness Impact Analysis (BIA)is the correct document thatidentifies critical servicesand definesRecovery Point Objectives (RPOs)andRecovery Time Objectives (RTOs). It helps organizations determine the impact of downtime and the maximum tolerable outages for business functions.

Disaster recovery plan (A)uses the information from the BIA.

Playbooks (C)are tactical and focus on specific incidents.

Backup plans (D)support BIA but don't define RPO/RTO themselves.

Comprehensive Detailed Explanation:To effectively prevent Cross-Site Scripting (XSS) attacks, implementing appropriate security controls within the application code and at the network layer is critical. Here’s a breakdown of each option:

A. Implement an IPS in front of the web server

Explanation: Intrusion Prevention Systems (IPS) are primarily designed to detect and prevent network-based attacks, not application-layer vulnerabilities such as XSS. They do not specifically mitigate XSS threats effectively.

B. Enable MFA on the website

Explanation: Multi-factor authentication (MFA) strengthens user authentication but does not address XSS, which typically involves injecting malicious scripts rather than compromising user credentials.

C. Take the website offline until it is patched

While this might temporarily mitigate the risk, it is not a practical solution for ongoing operations, especially when effective preventative controls (e.g., WAF rules or code updates) can be implemented without disabling the service.

D. Implement a compensating control in the source code

Explanation: Implementing security controls at the code level is an effective way to mitigate XSS risks. This can involve proper input validation, output encoding, and utilizing libraries that sanitize user inputs. By addressing the root cause in the source code, developers prevent scripts from being injected or executed in the browser.

E. Configure TLS v1.3 on the website

Explanation: While TLS v1.3 secures the communication channel, it does not address XSS directly. XSS attacks manipulate client-side scripts, which TLS cannot prevent, as TLS only encrypts data in transit.

F. Fix the vulnerability using a virtual patch at the WAF

Explanation: Web Application Firewalls (WAFs) can mitigate XSS vulnerabilities by identifying and blocking malicious payloads. Virtual patching at the WAF level provides a temporary fix by preventing exploit attempts from reaching the application, giving developers time to implement a permanent fix in the source code.

One of the best actions to take after the conclusion of a security incident to improve incident response in the future is to schedule a review with all teams to discuss what occurred, what went well, what went wrong, and what can be improved. This review is also known as a lessons learned session or an after-action report. The purpose of this review is to identify the root causes of the incident, evaluate the effectiveness of the incident response process, document any gaps or weaknesses in the security controls, and recommend corrective actions or preventive measures for future incidents. Official References: https://www.eccouncil.org/cybersecurity-exchange/threat-intelligence/cyber-kill-chain-seven-steps-cyberattack/

The takeown command is used to take ownership of a file or folder that previously was denied access to the current user or group12. The activity observed indicates that someone has taken ownership of all files and folders under the C:\Users\Documents\HR\Employees directory, which may contain sensitive or confidential information. This could be a sign of unauthorized privileges, as the user or group may not have the legitimate right or need to access those files or folders. Taking ownership of files or folders could also enable the user or group to modify or delete them, which could affect the integrity or availability of the data.

SVR02 has a CVSS score of 7.1 and is exploitable, making itthe highest priority for remediation​.

SVR01 (CVSS 8.9) is not exploitable, so it is a lower risk.

SVR03 (CVSS 3.5) is exploitablebut has alower severitythan SVR02.

SVR04 (CVSS 6.7) is not exploitable, reducing its urgency.

Thus,B (SVR02) is the correct answer, as it presentsthe highest immediate risk​.

The vulnerability that should be patched first, given the above third-party scoring system, is:

TSpirit: Cobain: Yes Grohl: Yes Novo: Yes Smear: No Channing: No

This vulnerability has three out of five metrics marked as Yes, which indicates a high severity level. The metrics Cobain, Grohl, and Novo are more important than Smear and Channing, according to the vulnerability management team. Therefore, this vulnerability poses a greater risk than the other vulnerabilities and should be patched first.

A single pane of glass is a term that describes a unified view or interface that integrates multiple tools or data sources into one dashboard or console. A single pane of glass can help improve security operations by providing visibility, correlation, analysis, and alerting capabilities across various security controls and systems. A single pane of glass can also help reduce complexity, improve efficiency, and enhance decision making for security analysts. In this case, a security program was able to achieve a 30% improvement in MTTR by integrating security controls into a SIEM, which provides a single pane of glass for security operations. Official References: https://www.eccouncil.org/cybersecurity-exchange/threat-intelligence/cyber-kill-chain-seven-steps-cyberattack

The suspicious entry on the host-based IDS logs indicates that a reverse shell was executed on the host, which connects to the remote IP address 10.1.2.3 on port 8080. The shell script option D uses the netstat command to check if there is any active connection to that IP address and port, and prints “Malicious activity” if there is, or “OK” otherwise. This is the most accurate way to confirm if the reverse shell is still active, as the other options may not detect the connection or may produce false positives.

ReferencesCompTIA CySA+ Study Guide: Exam CS0-003, 3rd Edition, Chapter 8: Incident Response, page 339.Reverse Shell Cheat Sheet, Bash section.

The correct answer is A. Address space layout randomization.

Address space layout randomization (ASLR) is a security control that randomizes the memory address space of a process, making it harder for an attacker to exploit memory-based vulnerabilities, such as buffer overflows1. ASLR can also prevent a security analyst from finding the proper memory address of a piece of malicious code, as the memory address changes every time the process runs2.

The other options are not the best explanations for why the memory address changes every time the process runs. Data execution prevention (B) is a security control that prevents code from being executed in certain memory regions, such as the stack or the heap3. Stack canary © is a security technique that places a random value on the stack before a function’s return address, to detect and prevent stack buffer overflows. Code obfuscation (D) is a technique that modifies the source code or binary of a program to make it more difficult to understand or reverse engineer. These techniques do not affect the memory address space of a process, but rather the execution or analysis of the code.

RCE stands for remote code execution, which is a type of attack that allows an attacker to execute arbitrary commands on a target system. The suspicious command in the question is an example of RCE, as it tries to download and execute a malicious file from a remote server using the wget and chmod commands. A buffer overflow is a type of vulnerability that occurs when a program writes more data to a memory buffer than it can hold, potentially overwriting other memory locations and corrupting the program’s execution. ICMP tunneling is a technique that uses ICMP packets to encapsulate and transmit data that would normally be blocked by firewalls or filters. A smurf attack is a type of DDoS attack that floods a network with ICMP echo requests, causing all devices on the network to reply and generate a large amount of traffic. Verified References: What Is Buffer Overflow? Attacks, Types & Vulnerabilities - Fortinet1, What Is a Smurf Attack? Smurf DDoS Attack | Fortinet2, exploit - Interpreting CVE ratings: Buffer Overflow vs. Denial of …3

The best security control to implement against sensitive information being disclosed via file sharing services is to improve employee training and awareness. Employee training and awareness can help educate employees on the risks and consequences of using file sharing services for sensitive information, as well as the policies and procedures for handling such information securely and appropriately. Employee training and awareness can also help foster a security culture and encourage employees to report any incidents or violations of information security.

The threat was detected from the time the emails were sent at 8:30 a.m. to when the recipients started alerting the organization’s help desk about the email at 8:45 a.m., taking a total of 15 minutes. The detection time is the time elapsed between the occurrence of an incident and its discovery by the security team . The other options are either too short or too long based on the given information. References: : Detection Time : Incident Response Metrics: Mean Time to Detect and Mean Time to Respond

SOAR (Security Orchestration, Automation and Response) and SIEM (Security Information and Event Management) are solutions that can help centralize the workload for the internal security team by collecting, correlating, and analyzing alerts from different sources, such as EDR. SOAR can also automate and streamline incident response workflows, while SIEM can provide dashboards and reports for security monitoring and compliance. References: What is EDR? Endpoint Detection & Response, How Does the Cyber Kill Chain Protect Against Attacks?; What is EDR Solution?, EDR solutions secure diverse endpoints through central monitoring

The system that should be prioritized for patching first is 54.74.110.228, as it has the highest number and severity of vulnerabilities among the four systems listed in the vulnerability report. According to the report, this system has 12 vulnerabilities, with 8 critical, 3 high, and 1 medium severity ratings. Thecritical vulnerabilities include CVE-2019-0708 (BlueKeep), CVE-2019-1182 (DejaBlue), CVE-2017-0144 (EternalBlue), and CVE-2017-0145 (EternalRomance), which are all remote code execution vulnerabilities that can allow an attacker to compromise the system without any user interaction or authentication. These vulnerabilities pose a high risk to the system and should be patched as soon as possible.

A CASB (Cloud Access Security Broker) is a security solution that acts as an intermediary between cloud users and cloud providers, and monitors and enforces security policies for cloud access and usage. A CASB can help organizations protect their data and applications in the cloud from unauthorized or malicious access, as well as comply with regulatory standards and best practices. A CASB can also provide visibility, control, and analytics for cloud activity, and identify and mitigate potential threats12

The other options are not correct. DMARC (Domain-based Message Authentication, Reporting and Conformance) is an email authentication protocol that helps email domain owners prevent spoofing and phishing attacks by verifying the sender’s identity and instructing the receiver how to handle unauthenticated messages34 SIEM (Security Information and Event Management) is a security solution that collects, aggregates, and analyzes log data from various sources across an organization’s network, such as applications, devices, servers, and users, and provides real-time alerts, dashboards, reports, and incident response capabilities to help security teams identify and mitigate cyberattacks56 PAM (Privileged Access Management) is a security solution that helps organizations manage and protect the access and permissions of users, accounts, processes, and systems that have elevated or administrative privileges. PAM can help prevent credential theft, data breaches, insider threats, and compliance violations by monitoring, detecting, and preventing unauthorized privileged access to critical resources78

Improving employee training and awareness is the best option to address the issue of sensitive reports being disclosed via file sharing services. By educating employees about the risks of unapproved file sharing, the security protocols to follow, and the proper channels to use for sharing company information, an organization can significantly reduce the risk of sensitive data being accidentally or intentionally shared on insecure platforms. This human-centric approach addresses the root cause of the problem. Options A, C, and D are security controls that do not directly address the behavior of sharing sensitive files on unauthorized services.

Comprehensive and Detailed Explanation From Exact Extract:

The scenario indicates the threat is still active and is appearing across multiple VMs in the same broadcast domain (suggesting lateral movement or propagation within that Layer 2 segment). Since quarantine of a single VM did not stop the threat, the appropriate next step is to broaden containment by isolating the affected subnet / network segment to prevent further spread.

The Sybex CySA+ Study Guide emphasizes that after identifying an incident in progress, responders should move into containment and that containment activities include segmentation and isolation:

Exact extract (Sybex Study Guide):

“After identifying a potential incident in progress, responders should take immediate action to contain the damage… Potential containment activities include network segmentation, isolation, and removal of affected systems.”

It also explains how segmentation (quarantine VLAN) is used to contain compromised systems and protect other systems:

Exact extract (Sybex Study Guide):

“During the early stages of an incident… [responders] built a separate virtual LAN (VLAN) to contain those systems… Putting the systems on this network segment provides some degree of isolation…”

Because the activity is occurring across the broadcast domain, isolating just one VM isn’t enough; the team should continue containment by isolating the subnet/segment where the issue is spreading (Option D). Moving to eradication (Option C) before containment is effective risks continued spread and loss of control.

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DNS exfiltration is a technique that uses the DNS protocol to transfer data from a compromised network or device to an attacker-controlled server. DNS exfiltration can bypass firewall rules and security products that do not inspect DNS traffic. The characteristics of the suspicious DNS traffic in the question match the indicators of DNS exfiltration, such as:

DNS traffic while a tunneling session is active: This implies that the DNS protocol is being used to create a covert channel for data transfer.

The mean time between queries is less than one second: This implies that the DNS queries are being sent at a high frequency to maximize the amount of data transferred.

The average query length exceeds 100 characters: This implies that the DNS queries are encoding large amounts of data in the subdomains or other fields of the DNS packets.

Official References:

https://partners.comptia.org/docs/default-source/resources/comptia-cysa-cs0-002-exam-objectives

https://resources.infosecinstitute.com/topic/bypassing-security-products-via-dns-data-exfiltration/

https://www.reddit.com/r/CompTIA/comments/nvjuzt/dns_exfiltration_explanation/

Rolling out a CDN is the best control to mitigate the Layer 4 DDoS attacks against the company website. A CDN is a Content Delivery Network, which is a system of distributed servers that deliver web content to users based on their geographic location, the origin of the web page, and the content delivery server. A CDN can help protect against Layer 4 DDoS attacks, which are volumetric attacks that aim to exhaust the network bandwidth or resources of the target website by sending a large amount of traffic, such as SYN floods, UDP floods, or ICMP floods. A CDN can mitigate these attacks by distributing the traffic across multiple servers, caching the web content closer to the users, filtering out malicious or unwanted traffic, and providing scalability and redundancy for the website12. References: How to Stop a DDoS Attack: Mitigation Steps for Each OSI Layer, Application layer DDoS attack | Cloudflare

Key pair authentication is a method of using a public and private key to securely access cloud resources, such as downloading the configuration of assets from a cloud tenancy. Key pair authentication is more secure than user and password or PAM, and does not require an additional factor like MFA.

Integrating an IT service delivery ticketing system to track remediation and closure is the best approach to ensure all vulnerabilities are patched in accordance with the SLA. A ticketing system is a software tool that helps manage, organize, and track the tasks and workflows related to IT service delivery, such as incident management, problem management, change management, and vulnerability management. A ticketing system can help the security team to prioritize, assign, monitor, and document the remediation of the vulnerabilities, and to ensure that they are completed within the specified time frame and quality standards. A ticketing system can also help the security team to communicate and collaborate with other teams, such as the IT operations team, the development team, and the business stakeholders, and to report on the status and progress of the remediation efforts12. Creating a compensating control item, accepting the risk, and requesting an exception are not the best approaches to ensure all vulnerabilitiesare patched in accordance with the SLA, as they do not address the root cause of the problem, which is the large number of critical and high findings that require patching. These approaches may also introduce more risks or challenges for the security team, such as compliance issues, resource constraints, or business impacts3 . References: What is a Ticketing System? | Freshservice ITSM Glossary, Vulnerability Management Best Practices, Compensating Controls: An Impermanent Solution to an IT … - Tripwire, [Risk Acceptance in Information Security - Infosec Resources], [Exception Management - ISACA]

Dynamic Application Security Testing (DAST) is used to detect vulnerabilities in running applications, including common issues like SQL injection, FRI, XSS, etc. It aligns with the goal of implementing security by design.

The best resource to ensure secure configuration of cloud infrastructure is A. CIS Benchmarks. CIS Benchmarks are a set of prescriptive configuration recommendations for various technologies, including cloud providers, operating systems, network devices, and server software. They are developed by a global community of cybersecurity experts and help organizations protect their systems against threats more confidently1

PCI DSS, OWASP Top Ten, and ISO 27001 are also important standards for information security, but they are not focused on providing specific guidance for hardening cloud infrastructure. PCI DSS is a compliance scheme for payment card transactions, OWASP Top Ten is a list of common web application security risks, and ISO 27001 is a framework for establishing and maintaining an information security management system. These standards may have some relevance for cloud security, but they are not as comprehensive and detailed as CIS Benchmarks

A social engineering attack is a type of cyberattack that relies on manipulating human psychology rather than exploiting technical vulnerabilities. A social engineering attack may involve deceiving, persuading, or coercing users into performing actions that benefit the attacker, such as clicking on malicious links, divulging sensitive information, or granting access to restricted resources. An obfuscated link is a link that has been disguised or altered to hide its true destination or purpose. Obfuscated links are often used by attackers to trick users into visiting malicious websites or downloading malware. In this case, an incident response analyst notices multiple emails traversing the network that target only the administrators of the company. The email contains a concealed URL that leads to an unknown website in another country. This indicates that the analyst is witnessing a social engineering attack using obfuscated links.

APIs (Application Programming Interfaces) enable integration and automation across different vendor platforms within a SOAR (Security Orchestration, Automation, and Response) solution. They allow security tools to communicate and execute automated actions, making them essential for orchestrating responses across diverse systems and platforms. While STIX/TAXII provides standards for threat information sharing, and data enrichment enhances context, APIs are the primary means of enabling cross-platform automation, as recommended in CompTIA CySA+ materials on SOAR operations.

EDR stands for Endpoint Detection and Response, which is a tool that collects and aggregates data from various endpoints, such as laptops, servers, or mobile devices. EDR helps analysts monitor, detect, and respond to threats and incidents on the endpoints. EDR is more suitable than DLP (Data Loss Prevention), NAC (Network Access Control), or NIDS (Network Intrusion Detection System) for data collection and aggregation from endpoints.

During an incident, the legal team plays a crucial role in handling regulatory compliance and reviewing legal implications, such as contractual obligations and reporting requirements. Advising on regulatory reporting (Option C) ensures the organization meets legal mandates, while reviewing contracts (Option B) can address new or emergency services needed during the incident. According to CompTIA CySA+ and Security+ guidelines, these legal responsibilities are vital for compliance and risk management.Options related to staffing, damage assessments, and clearances typically fall under operational or HR responsibilities rather than legal purview.

To determine the correct priority, you must filter the options by applying the rules from Security Policy 1006 in the order of importance dictated by the scenario.

“The Company shall prioritize patching of publicly available systems and services over patching of internally available system.”

Option A: Internal System

Option B: External System (Keep)

Option C: External System (Keep)

Option D: Internal System

Result: Eliminate Options A and D. We are now choosing between B and C.

“In situations where a choice must be made between confidentiality and availability, the Company shall prioritize confidentiality of data over availability of systems and data.”

To apply this, you must read the CVSS v3.1 Vector String for the remaining options. The relevant metrics are C (Confidentiality) and A (Availability).

Option B (CAP.SHIELD): C:H / I:N / A:N

Confidentiality: High (C:H)

Availability: None (A:N)

Interpretation: This vulnerability allows for a significant breach of data confidentiality.

Option C (LOKI.DAGGER): C:N / I:N / A:H

Confidentiality: None (C:N)

Availability: High (A:H)

Interpretation: This vulnerability allows for a significant disruption of service (DoS).

Conclusion: Since the policy explicitly prioritizes Confidentiality (Option B) over Availability (Option C), Option B is the highest priority.

The exam expects you to parse raw CVSS strings to assess risk. Here is the breakdown for the correct answer (Option B):

Metric

Code

Value

Meaning

AV

AV:N

Network

The vulnerability is exploitable remotely via the network (most dangerous).

AC

AC:L

Low

No complex conditions are required to exploit.

PR

PR:N

None

No privileges are required (unauthenticated).

UI

UI:N

None

No user interaction is required.

C

C:H

High

Confidentiality Impact. Total loss of confidentiality.

A

A:N

None

Availability Impact. No impact to uptime.

Proprietary systems are systems that are owned and controlled by a specific vendor or manufacturer, and that use proprietary standards or protocols that are not compatible with other systems. Proprietary systems can pose a challenge for vulnerability management, as they may not allow users to access or modify their configuration, update their software, or patch their vulnerabilities. In this case, two of the critical systems cannot be upgraded due to a vendor appliance that the company does not have access to. This indicates that these systems and associated vulnerabilities are examples of proprietary systems as inhibitors to remediation

The correct answer is D. MITRE ATT&CK.

MITRE ATT&CK is a framework that maps the tactics, techniques, and procedures (TTPs) of various threat actors and groups, based on real-world observations and data. MITRE ATT&CK can help a Chief Information Security Officer (CISO) to map all the attack vectors that the company faces each day, as well as to align their security controls around the most relevant and prevalent threats. MITRE ATT&CK can also help the CISO to assess the effectiveness and maturity of their security posture, as well as to identify and prioritize the gaps and improvements .

The other options are not the best recommendations for mapping all the attack vectors that the company faces each day. OSSTMM (Open Source Security Testing Methodology Manual) (A) is a methodology that provides guidelines and best practices for conducting security testing and auditing, but it does not map the TTPs of threat actors or groups. Diamond Model of Intrusion Analysis (B) is a model that analyzes the relationships and interactions between four elements of an intrusion: adversary, capability, infrastructure, and victim. The Diamond Model can help understand the characteristics and context of an intrusion, but it does not map the TTPs of threat actors or groups. OWASP (Open Web Application Security Project) © is a project that provides resources and tools for improving the security of web applications, but it does not map the TTPs of threat actors or groups.

The primary purpose ofdata classificationis to determine the value of data to the organization. This helps in definingprotection levels, access controls, and risk mitigation strategies.

Option A (Regulatory compliance requirements)is important but not the primary reason. Compliance is a result of data classification, not its purpose.

Option B (Facilitating DLP rules)is a secondary benefit, but classification is broader and not limited to DLP.

Option C (Prioritizing IT expenses)is unrelated to why organizations classify data​.

Thus,D is the correct answer, asclassification helps organizations prioritize data protection based on its value.

In case of a phishing attack, it’s crucial to review what actions were taken by the employee and analyze the phishing email to understand its nature and impact.References: CompTIA CySA+ Study Guide: Exam CS0-003, 3rd Edition, Chapter 6, page 246; CompTIA CySA+ CS0-003 Certification Study Guide, Chapter 6, page 255.

The output shows the result of running the ssl-enum-ciphers script with Nmap, which is a tool that can scan web servers for supported SSL/TLS cipher suites. Cipher suites are combinations of cryptographic algorithms that are used to establish secure communication between a client and a server. The output shows the cipher suites that are supported by the server, along with a letter grade (A through F) indicating the strength of the connection. The output also shows the least strength, which is the strength of the weakest cipher offered by the server. In this case, the least strength is F, which means that the server is allowing insecure cipher suites that are vulnerable to attacks or have been deprecated. For example, the output shows that the server supports SSLv3, which is an outdated and insecure protocol that is susceptible to the POODLE attack. The output also shows that the server supports RC4, which is a weak and broken stream cipher that should not be used. Therefore, the best description of the output is that the host is allowing insecure cipher suites. The other descriptions are not accurate, as they do not reflect what the output shows. The host is not up or responding is incorrect, as the output clearly shows that the host is up and responding to the scan. The host is running excessive cipher suites is incorrect, as the output does not indicate how many cipher suites the host is running, only which ones it supports. The Secure Shell port on this host is closed is incorrect, as the output does not show anything about port 22, which is the default port for Secure Shell (SSH). The output only shows information about port 443, which is the default port for HTTPS.

The CISO’s requirements prioritize protecting customer (sensitive) data with encryption both in transit and at rest. The database that violates the most critical requirements—especially for sensitive/customer data—should be remediated first.

Why Database4 is the highest priority

Sensitive data + no encryption in transit (Port 80): Port 80 indicates HTTP (clear-text), which means no encryption in transit. Secbay explicitly states: “HTTP is a clear-text protocol that is generally secured via an SSL/TLS tunnel to produce HTTPS transmission.”

Uses weak/unsupported TLS version (TLS 1.1) + sensitive data: Even if TLS is “listed,” TLS 1.1 is not considered acceptable in modern secure configurations. Secbay’s protocol acceptability list marks TLS 1.1 = No (not acceptable), while TLS 1.2/1.3 are acceptable.

Customer data must be encrypted in transit and at rest: Secbay provides the exact requirement-style statement: “The organization implements encryption for sensitive data both in transit and at rest… Sensitive customer data is encrypted…”

So Database4 is the most severe because it involves Sensitive (customer) data while failing the “encryption in transit” requirement (HTTP/80) and also relying on an unacceptable TLS version (1.1).

Why the other databases are lower priority

Database3: TLS 1.2 on 443 + encryption at rest enabled + sensitive data → it already meets the CISO requirements.

Database2: Port 80 (no transit encryption) and encryption at rest disabled, but the data type is proprietary, not explicitly customer/sensitive. It is still important, but Database4 is worse because it impacts sensitive/customer data.

Database1: Data type is public; while TLS 1.1 is weak, it does not violate the “customer data” requirement and is less severe than Database4’s clear-text transport for sensitive data.

References (CompTIA CySA+ CS0-003 documents / study guides used):

Secbay Press, CompTIA CySA+ Exam Prep Guide (CS0-003): encrypt sensitive customer data in transit and at rest

Secbay Press, CompTIA CySA+ Exam Prep Guide (CS0-003): HTTP is clear-text; TLS 1.1 not acceptable while TLS 1.2/1.3 are acceptable

A new program has been set to execute on system start is the most likely cause of the suspicious activity that is occurring, as it indicates that the malware has modified the registry keys of the system to ensure its persistence. File Integrity Monitoring (FIM) is a tool that monitors changes to files and registry keys on a system and alerts the security analyst of any unauthorized or malicious modifications. The alert triggered by FIM shows that the malware has created a new registry key under the Run subkey, which is used to launch programs automatically when the system starts. The new registry key points to a file named “update.exe” in the Temp folder, which is likely a malicious executable disguised as a legitimate update file. Official References:

https://www.comptia.org/blog/the-new-comptia-cybersecurity-analyst-your-questions-answered

https://partners.comptia.org/docs/default-source/resources/comptia-cysa-cs0-002-exam-objectives

https://www.comptia.org/training/books/cysa-cs0-002-study-guide

Using aregular expression (regex)to search email logs is the most efficient and scalable way to identify patterns in phishing URLs. Phishing campaigns often use consistent URL formats across different domains. Regex allows administrators to define flexible patterns to match these URLs even when the domains vary. This is significantly more effective than relying on user reports or less granular tools like firewall logs for such cases.

The incident response policy or plan is a document that defines the roles and responsibilities, procedures and processes, communication and escalation protocols, and reporting and documentation requirements for handling security incidents. The lead should review what is documented in the incident response policy or plan to determine who should be communicated with and when during a security incident, as well as what information should be shared and how. The incident response policy or plan should also be aligned with the organizational policies and legal obligations regarding incident notification and disclosure.

The discovery of unapproved accounts accessing shared data, along with data discrepancies, strongly indicates unauthorized changes.

Indicators of Unauthorized Changes:

Unexpected user permissions found during audits​.

Modified or deleted data without proper documentation.

Altered system or security configurations, allowing unintended access.

Why Not Other Options?

A. Filesystem Anomaly: This refers to unexpected behavior in the file structure, such as corrupt metadata or missing files, rather than unauthorized user access.

B. Illegal Software: Would involve unlicensed or unauthorized applications, not unauthorized file modifications.

D. Data Exfiltration: If data was removed, it might be exfiltration, but in this case, data modifications were detected instead.

To prevent unauthorized changes, security teams should use:

File Integrity Monitoring (FIM) to detect unauthorized modifications.

Access control audits to verify correct user permissions.

SIEM tools to analyze logs for anomalies.

 The script uses PowerShell syntax, such as cmdlets, parameters, variables, and comments. PowerShell is a scripting language that can be used to automate tasks and manage systems.

The one-liner script is utilizing JavaScript to execute a PowerShell command that downloads and runs a script from an external source, indicating the use of custom malware to download an additional script. References: CompTIA CySA+ Study Guide: Exam CS0-003, 3rd Edition, Chapter 4: Security Operations and Monitoring, page 156.

Comprehensive and Detailed Step-by-Step Explanation:The SPF = PASS result confirms the email came from an authorized server, but DKIM = FAIL indicates the message was not properly signed with the expected DomainKeys Identified Mail (DKIM) signature. DMARC = FAIL suggests that because DKIM failed, the overall email authentication failed. This scenario is consistent with a legitimate server sending an unsigned email.

A security analyst’s concern is that any discovered vulnerabilities in the OS that is approaching the end-of-life date will not be remediated by the vendor, leaving the system exposed to potential attacks. The other options are not directly related to the security analyst’s role or responsibility. Verified References: CompTIA Cybersecurity Analyst (CySA+) Certification Exam Objectives, page 9, section 2.21

Performing input validation before allowing submission is the best recommendation for remediation of this application vulnerability. Input validation is a technique that checks the data entered by users or attackers against a set of rules or constraints, such as data type, length, format, or range. Input validation can prevent common web application attacks such as SQL injection, cross-site scripting (XSS), or command injection, which exploit the lack of input validation to execute malicious code or commands on the server or the client side. By validating the input before allowing submission, the web application can reject or sanitize any malicious or unexpected input, and protect the user credentials and other sensitive data from being compromised12. References: Input Validation - OWASP, 4 Most Common Application Vulnerabilities and Possible Remediation

D ("grnail.com") is a suspicious domain that resembles "gmail.com."

The high "bytes out" value (525,984 bytes) indicates potential data exfiltration.

Attackers often use typosquatting (e.g., "grnail.com" instead of "gmail.com") to trick users into visiting malicious sites.

Why Not Other Options?

A (Netflix, B YouTube, C TikTok) → Large downloads, but expected behavior for streaming sites.

E (Google Translate) → Low data volume, no exfiltration risk.

F (Office.com) → Microsoft service, no indication of malicious activity.

An incident response timeline is a detailed chronological record of all events and actions taken during the response to a security incident. It includes timestamps and descriptions of each step, providing a comprehensive overview of how the incident was detected, contained, mitigated, and resolved. This timeline is crucial for post-incident analysis, helping to understand the effectiveness of the response, identify areas for improvement, and ensure accountability and transparency in the incident handling process.

A sandbox environment is a safe and isolated way to analyze malware without affecting the organization’s network. An online service can provide a sandbox environment without requiring the security analyst to set up a virtual host or use an RDP session. Disconnecting and using an existing infected asset is risky and may not provide accurate results. References: Malware Analysis: Steps & Examples, Dynamic Analysis

The analyst should look at p4wnp1_aloa.lan (192.168.86.56) first, as this is the most suspicious device on the network. P4wnP1 ALOA is a tool that can be used to create a malicious USB device that can perform various attacks, such as keystroke injection, network sniffing, man-in-the-middle, or backdoor creation. The presence of a device with this name on the network could indicate that an attacker has plugged in a malicious USB device to a system and gained access to the network. Official References: https://github.com/mame82/P4wnP1_aloa

Non-repudiation ensures that a message sender cannot deny the authenticity of their sent message. This is crucial in banking communications for legal and security reasons.

The goal of allowing a message recipient to prove the message's origin is non-repudiation. This ensures that the sender cannot deny the authenticity of their message. Non-repudiation is a fundamental aspect of secure messaging systems, especially in banking and financial communications.

The most likely reason to include lessons learned in an after-action report is to identify areas of improvement in the incident response process. The lessons learned process is a way of reviewing and evaluating the incident response activities and outcomes, as well as identifying and documenting any strengths, weaknesses, gaps, or best practices. Identifying areas of improvement in the incident response process can help enhance the security posture, readiness, or capability of the organization for future incidents, as well as provide feedback or recommendations on how to address any issues or challenges.

Developing an organization's communication plans is crucial to ensure that incidents, especially those involving sensitive data like PH (Protected Health) data, are promptly reported to the relevant regulatory agencies. This is essential for compliance with legal and regulatory requirements, which often mandate timely notification of data breaches. Effective communication plans help the organization manage the breach response process, mitigate potential legal penalties, and maintain transparency with regulatory bodies.

Microsegmentation involves dividing a network into smaller, isolated segments to restrict lateral movement within the network. This is crucial within a Zero Trust architecture, which assumes that no entity (internal or external) is inherently trustworthy. By limiting access to only necessary network segments, microsegmentation reduces the impact of a potential breach by containing it within a limited area. CompTIA emphasizes microsegmentation as an effective strategy to minimize risk and improve security posture by isolating resources based on the principle of least privilege.

The Command and Control stage of the Cyber Kill Chain describes the communication between the attacker and the compromised system. The attacker may use this channel to send commands, receive data, or update malware. If the analyst discovers unusual outbound connections to an IP that was previously blocked, it may indicate that the attacker has established a command and control channel and bypassed the security controls. References: Cyber Kill Chain® | Lockheed Martin

A compensating control is an alternative measure that provides a similar level of protection as the original control, but is used when the original control is not feasible or cost-effective. In this case, the CISO should develop a compensating control to mitigate the risk of the vulnerability in the ACE software, such as implementing additional monitoring, firewall rules, or encryption, until the issue can be fixed permanently by the developers. References: CompTIA CySA+ Study Guide: Exam CS0-003, 3rd Edition, Chapter 5, page 197; CompTIA CySA+ CS0-003 Certification Study Guide, Chapter 5, page 205.

To decide what to address first, CySA+ expects a risk-based prioritization approach, combining factors like:

Asset criticality/value (business impact)

Exposure/architecture (internet-facing vs. isolated/internal)

Patch availability / ability to remediate quickly

Exploitability / likelihood of exploitation

1) Server5 (Critical + Patch Yes) — prioritize immediately

Server5 sits in the database network, is marked Critical, and a patch is available. That combination makes it one of the highest priorities because you can rapidly reduce risk on an asset with the greatest business impact.

Secbay explicitly states that prioritization should align to asset criticality and business impact, and also notes that patch availability accelerates remediation:Exact extract (Secbay Press): “Prioritize vulnerabilities based on their severity, exploitability, and potential impact… Asset Criticality: Identify and prioritize vulnerabilities based on the criticality of the assets they affect…” and “Patch Availability… Action: Prioritize vulnerabilities for which patches are readily available, as prompt remediation is possible.”

The All-in-One guide emphasizes asset value/criticality as a major driver of how fast you remediate:Exact extract (All-in-One Exam Guide): “Asset value is likely one of the most important factors in determining how quickly you should remediate vulnerabilities…”

2) Server3 (Perimeter + High) — address immediately (mitigate now, patch later)

Server3 is in the perimeter network and rated High, making it more exposed to attack paths than internal-only systems. Even though no patch is available, the analyst must still “address” it first via mitigation/compensating controls (segmentation, firewalling, disabling vulnerable services, WAF where relevant, tighter ACLs, etc.) because perimeter exposure increases likelihood of exploitation.

The All-in-One guide makes the architecture/exposure point very directly:Exact extract (All-in-One Exam Guide – Exam Tip): “The architecture of your infrastructure should be a factor… Internet-facing hosts with sensitive information will likely be your highest priority, while isolated systems… may be able to wait a bit longer for remediation.”

Secbay’s prioritization guidance also highlights focusing on critical/high impact risks first and using risk-based prioritization.

Why not the others (briefly):

Server4 (Internal, High, Patch Yes): This is a strong candidate, but when choosing only two, perimeter high exposure (Server3) plus critical database with patch (Server5) generally outranks an internal high system.

Server2 (Perimeter, Low, Patch Yes): Exposed, but Low criticality.

Server1 / Server6 (Medium, No patch): Lower criticality and no patch—typically handled after higher-risk items, or mitigated as feasible.

References (CompTIA CySA+ CS0-003 documents / study guides used):

Mya Heath et al., CompTIA CySA+ All-in-One Exam Guide (CS0-003): infrastructure architecture affects remediation priority; internet-facing hosts are typically highest priority; asset value drives remediation urgency

Secbay Press, CompTIA CySA+ Exam Prep Guide (CS0-003): vulnerability prioritization factors include asset criticality and patch availability; prioritize items with readily available patches for prompt remediation

According to the CompTIA CySA+ Study Guide: Exam CS0-003, 3rd Edition1, the best technique to provide the necessary assurance for embedded software that drives centrifugal pumps at a power plant is formal methods. Formal methods are a rigorous and mathematical approach to software development and verification, which can ensure the correctness and reliability of critical software systems. Formal methods can be used to specify, design, implement, and verify embedded software using formal languages, logics, and tools1.

Containerization, manual code reviews, and static and dynamic analysis are also useful techniques for software assurance, but they are not as rigorous or comprehensive as formal methods. Containerizationis a method of isolating and packaging software applications with their dependencies, which can improve security, portability, and scalability. Manual code reviews are a process of examining the source code of a software program by human reviewers, which can help identify errors, vulnerabilities, and compliance issues. Static and dynamic analysis are techniques of testing and evaluating software without executing it (static) or while executing it (dynamic), which can help detect bugs, defects, and performance issues1.

A prioritized list of critical systems defined by executive leadership is the best option to use to develop a business continuity plan. A business continuity plan (BCP) is a system of prevention and recovery from potential threats to a company. The plan ensures that personnel and assets are protected and are able to function quickly in the event of a disaster1. A BCP should include a business impact analysis, which identifies the critical systems and processes that are essential for the continuity of the business operations, and the potential impacts of their disruption2. The executive leadership should be involved in defining the critical systems and their priorities, as they have the strategic vision and authority to make decisions that affect the whole organization3. A diagram of all systems and interdependent applications, a repository for all the software used by the organization, and a configuration management database in print at an off-site location are all useful tools for documenting and managing the IT infrastructure, but they are not sufficient to develop a comprehensive BCP that covers all aspects of the business continuity4. References: What Is a Business Continuity Plan (BCP), and How Does It Work?, Business continuity plan (BCP) in 8 steps, with templates, Business continuity planning | Business Queensland, Understanding the Essentials of a Business Continuity Plan

Weaponization is the stage of the Cyber Kill Chain where the threat actor creates or modifies a malicious tool to use against a target. In this case, the threat actor compiles and tests a malicious downloader, which is a type of weaponized malware. References: Cybersecurity 101, The Cyber Kill Chain: The Seven Steps of a Cyberattack

Conducting regular code reviews using OWASP best practices is the most effective action to reduce risks associated with the application development. Code reviews are a systematic examination of the source code of an application to detect and fix errors, vulnerabilities, and weaknesses that may compromise the security, functionality, or performance of the application. Code reviews can help to improve the quality and security of the code, as well as to identify and remediate common security risks, such as insufficient logging capabilities. OWASP (Open Web Application Security Project) is a global nonprofit organization that provides free and open resources, tools, standards, and best practices for web application security. OWASP best practices for logging include following a common loggingformat and approach, logging relevant security events and data, protecting log data from unauthorized access or modification, and using log analysis and monitoring tools to detect and respond to security incidents. By following OWASP best practices for logging, developers can ensure that their web applications have sufficient and effective logging capabilities that can help to prevent, detect, and mitigate security threats.

Abackdooris a deliberate vulnerability inserted into the code, often allowing unauthorized access.

Source code review (Option D)is the best way to detect malicious code before it is deployed to production.

SDLC training (Option A)is helpful but does not directly prevent the insertion of backdoors.

Dynamic analysis (Option B)detects vulnerabilities at runtime but may not always identify backdoors in code.

Debugging (Option C)is useful for troubleshooting but does not address security vulnerabilities.

????Reference:CompTIA CySA+ CS0-003 Official Study Guide, Secure Software Development Practices.

The output shows the results of a port scan, which is a technique used to identify open ports and services running on a network host. Port scanning can be used by attackers to discover potential vulnerabilities and exploit them, or by defenders to assess the security posture and configuration of their network devices1

The output lists six ports that are open on the target host, along with the service name and version associated with each port. The service name indicates the type of application or protocol that is using the port, while the version indicates the specific release or update of the service. The service name and version can provide useful information for both attackers and defenders, as they can reveal the capabilities, features, and weaknesses of the service.

Among the six ports listed, two are particularly risky and should be investigated further by the security team: port 23 and port 636.

Port 23 is used by Telnet, which is an old and insecure protocol for remote login and command execution. Telnet does not encrypt any data transmitted over the network, including usernames and passwords, which makes it vulnerable to eavesdropping, interception, and modification by attackers. Telnet also has many known vulnerabilities that can allow attackers to gain unauthorized access, execute arbitrary commands, or cause denial-of-service attacks on the target host23

Port 636 is used by LDAP over SSL/TLS (LDAPS), which is a protocol for accessing and modifying directory services over a secure connection. LDAPS encrypts the data exchanged between the client and the server using SSL/TLS certificates, which provide authentication, confidentiality, and integrity. However, LDAPS can also be vulnerable to attacks if the certificates are not properly configured, verified, or updated. For example, attackers can use self-signed or expired certificates to perform man-in-the-middle attacks, spoofing attacks, or certificate revocation attacks on LDAPS connections.

Therefore, the security team should investigate further why port 23 and port 636 are open on the target host, and what services are running on them. The security team should also consider disabling or replacing these services with more secure alternatives, such as SSH for port 23 and StartTLS for port 6362

Command-and-control (C2) beaconing involves compromised systems communicating with an attacker’s server at regular intervals, often using HTTPS to blend in with legitimate traffic. This is indicative of a potential compromise where malware communicates back to a command center. The persistent nature of the connections after hours and throughout the day suggests automated beaconing, which is a tell-tale sign of C2 activity. According to CompTIA CySA+, this type of activity should raise immediate suspicion and warrants further investigation and containment. While options B, C, D, and E might indicate other issues, they do not fit the pattern described as well as option A.

The vulnerability scan shows that the version information is visible in the http-server-header, which can be exploited by attackers to identify vulnerabilities specific to that version. Removing or obfuscating this information can enhance security.

Comprehensive and Detailed Explanation From Exact Extract:

The error messages point to two core issues common in cloud assessments:

Authentication error → credentials/API access not correctly configured (keys/tokens/CLI auth).

Instance not found on preset location → the tool is looking in the wrong region/location (cloud resources are region-scoped).

Cloud infrastructure assessment tools typically require API-based access and allow configuration to include/exclude regions. The All-in-One guide explains that cloud tools like Scout Suite and Prowler work via cloud APIs and require configuration to enable programmatic access, and Prowler specifically can include/exclude regions:

Exact extract (All-in-One Exam Guide): Scout Suite “works by managing the interactions with cloud assets via the platform API…”

Exact extract (All-in-One Exam Guide): “Prowler offers a fair amount of configuration to allow the tool programmatic access via the Amazon API…”

Exact extract (All-in-One Exam Guide): Prowler “provides the option to… include or exclude certain AWS services or regions…”

These extracts support why the fix is to set the correct region and ensure valid authentication/keys, which maps directly to Option C (set_regions … and set_key).

Why the other options don’t match the errors:

A / B look like generic module/session execution flags (more like exploitation frameworks), not “fix authentication + wrong region.”

D (--whoami, --data) is identity/data querying; it doesn’t correct credential setup or region selection.

References (CompTIA CySA+ CS0-003 documents / study guides used):

All-in-One CS0-003: Scout Suite uses cloud provider APIs; Prowler requires API access configuration and supports region selection/exclusion

3 High (10-25) - actual score was 15

8 Low (0-4) - actual score was 2

2 High (10-25) - actual score was 20

6 Low (0-4) - actual score was 4

7 Low (0-4) - actual score was 3

1 High (10-25) - actual score was 25

4 Medium (5-9) - actual score was 9

5 Medium (5-9) - actual score was 6

The first step for the security team when receiving a legal hold request is to notify the relevant departments to preserve all potentially relevant information. This ensures that no data is altered, deleted, or otherwise tampered with, which is critical for maintaining the integrity of the evidence. Preserving information includes emails, documents, and any other data that might be relevant to the legal matter. Establishing a chain of custody and backing up data are also important steps, but notifying the involved parties is the immediate priority to prevent data loss.

The next step in the remediation process after applying a software patch is validation. Validation is a process that involves verifying that the patch has been successfully applied, that it has fixed the vulnerability, and that it has not caused any adverse effects on the system or application functionality or performance. Validation can be done using various methods, such as scanning, testing, monitoring, or auditing.

The correct answer is A. Implanted a backdoor.

A backdoor is a method that allows an unauthorized user to access a system or network without the permission or knowledge of the owner. A backdoor can be installed by exploiting a software vulnerability, by using malware, or by physically modifying the hardware or firmware of the device. A backdoor can be used for various malicious purposes, such as stealing data, installing malware, executing commands, or taking control of the system.

In this case, the consultant implanted a backdoor in the website by using an HTML and PHP code snippet that displays an image of a shutdown button and an alert message that says “Exit”. However, the code also echoes the remote address of the server, which means that it sends the IP address of the visitor to the attacker. This way, the attacker can identify and target the visitors of the website and use their IP addresses to launch further attacks or gain access to their devices.

The code snippet is an example of a clickjacking attack, which is a type of interface-based attack that tricks a user into clicking on a hidden or disguised element on a webpage. However, clickjacking is not the main goal of the consultant, but rather a means to implant the backdoor. Therefore, option C is incorrect.

Option B is also incorrect because privilege escalation is an attack technique that allows an attacker to gain higher or more permissions than they are supposed to have on a system or network. Privilege escalation can be achieved by exploiting a software vulnerability, by using malware, or by abusing misconfigurations or weak access controls. However, there is no evidence that the consultant implemented privilege escalation on the website or gained any elevated privileges.

Option D is also incorrect because patching is a process of applying updates to software to fix errors, improve performance, or enhance security. Patching can prevent or mitigate various types of attacks, such as exploits, malware infections, or denial-of-service attacks. However, there is no indication that the consultant patched the web server or improved its security in any way.

SQL injection is a type of attack that injects malicious SQL statements into a web application’s input fields or parameters, in order to manipulate or access the underlying database. The request shown in the image contains an SQL injection attempt, as indicated by the “UNION SELECT” statement, which is used to combine the results of two or more queries. The attacker is trying to extract information from the database by appending the malicious query to the original one

Root Cause Analysis (RCA)is the best approach toidentify and resolve the underlying cause of recurring incidents. It involves a systematic investigation of logs, configurations, and operational data to pinpoint the reason behindpersistent security issues​.

Option A (Vulnerability assessment)helpsidentify security weaknessesbut does not focus onrecurring operational issues.

Option C (Recurrence reports)trackpatternsbut do notresolve the root cause.

Option D (Lessons learned)is valuable but is typicallya post-mortem discussion rather than an investigative method.

Thus,B is the correct answer, asroot cause analysis is the best approach for diagnosing recurring availability issues​.

The formal incident declaration is crucial to identify and document the staff who have the authority to declare an incident, ensuring that incidents are handled by authorized personnel. References: CompTIA CySA+ Study Guide: Exam CS0-003, 3rd Edition, Chapter 5: Incident Response, page 197.

Testing is a crucial step in any change management process, as it ensures that the change is compatible with the existing systems and does not cause any errors or disruptions. In this case, the change management team failed to test the email client patch on Windows 11 devices, which resulted in a widespread issue for the users. Testing would have revealed the problem before the patch was deployed, and allowed the team to fix it or postpone the change.

The most likely cause of the issue where an ICS (Industrial Control System) could not be updated due to hardware versioning incompatibility is a legacy system. Legacy systems often have outdated hardware and software that may not be compatible with modern updates and patches. This can pose significant challenges in maintaining security and operational efficiency.

SOAR stands for Security Orchestration, Automation and Response, which is a set of features that can help security teams manage, prioritize and respond to security incidents more efficiently and effectively. SOAR can help decrease the workload without increasing staff by automating repetitive tasks, streamlining workflows, integrating different tools and platforms, and providing actionable insights and recommendations. SOAR is also one of the current trends that CompTIA CySA+ covers in its exam objectives. Official References:

https://www.comptia.org/blog/the-new-comptia-cybersecurity-analyst-your-questions-answered

https://www.comptia.org/certifications/cybersecurity-analyst

https://partners.comptia.org/docs/default-source/resources/comptia-cysa-cs0-002-exam-objectives

When acritical vulnerabilityis identified, the immediate next step should be toassess the riskassociated with the vulnerability.

Risk assessment (Option B)helps determine the severity, exploitability, and business impact before deciding on mitigation measures.

Option A (delaying the fix)is dangerous because payment data theft can have severe consequences, including regulatory penalties and reputational damage.

Option C (ignoring the vulnerability)is incorrect because passing a compliance audit does not mean the system is secure.

Option D (isolating and reimaging)is an extreme measure that might not be necessary unless active exploitation is detected.

????Reference:CompTIA CySA+ CS0-003 Official Study Guide, Risk Management & Vulnerability Management Lifecycle.

A vulnerability that is related to a specific adversary campaign, with IoCs found in the SIEM, should have the highest priority for the mitigation process. This is because it indicates that the vulnerability is actively being exploited by a known threat actor, and that the organization’s security monitoring system has detected signs of compromise. This poses a high risk of data breach, service disruption, or other adverse impacts. References: How to Prioritize Vulnerabilities Effectively: Vulnerability Prioritization Explained, Section: How to prioritize vulnerabilities step by step to avoid drowning in sea of problems; CompTIA CySA+ Study Guide: Exam CS0-003, 3rd Edition, Chapter 4: Security Operations and Monitoring, page 156.

When a patch cannot be deployed due to conflicting routine system upgrades, updating the risk register and requesting a change to the Service Level Agreement (SLA) is a practical approach. It allows for re-evaluation of the risk and adjustment of the SLA to reflect the current situation.

PID 2264 (bash running as root) is suspicious because:

It has elevated privileges (root user).

Bash (command-line shell) is running with high CPU usage (14.0%), which is unusual unless actively being used.

If unauthorized, an attacker could be exfiltrating data via command-line methods like scp, wget, or custom scripts.

Why Not Other Options?

B (34218 - Xorg) → Xorg is a display server for GUI; no signs of exfiltration.

C (34834 - Cinnamon) → Cinnamon is a desktop environment, not a threat.

D (35963 - xrdp) → xrdp is a remote desktop service, expected behavior.

Wireshark is a network protocol analyzer that allows analysts to capture and inspect data packets traveling through a network. This makes it ideal for investigating unusual network activity, as it provides detailed insights into the nature and content of network traffic. In this case, Wireshark can help identify potentially malicious packets and understand the nature of the observed traffic. Options A (WAF) and C (EDR) are primarily used for monitoring and protecting web applications and endpoints, respectively, and Nmap (D) is typically used for network discovery and mapping, not detailed traffic analysis. According to CompTIA CySA+, packet analysis tools like Wireshark are invaluable for deep-dive investigations into network anomalies.

Brady should be prioritized for remediation, as it has the highest risk score and the highest number of affected users. The risk score is calculated by multiplying the CVSS score by the exposure factor, which is the percentage of systems that are vulnerable to the exploit. Brady has a risk score of 9 x 0.8 = 7.2, which is higher than any other system. Brady also has 500 affected users, which is more than any other system. Therefore, patching brady would reduce the most risk and impact for the organization. The other systems have lower risk scores and lower numbers of affected users, so they can be remediated later.

Reimaging the device is the most effective way to eliminate persistent malware because some sophisticated malware, such as rootkits and firmware-level threats, can survive traditional scans and removals.

If a system keeps getting reinfected after cleaning, it may indicate a deeply embedded persistent threat, possibly in:

The Master Boot Record (MBR) or EFI firmware.

A compromised system restore point.

A hidden backdoor left by the malware.

Why Not Other Options?

A (Update and scan in safe mode) → Might help, but if malware is persistent, it will likely return.

C (Upgrade OS) → Does not necessarily remove malware; some malware survives OS upgrades.

D (Secondary scanner) → Useful for detection but does not guarantee complete removal.

Best Practice:

Replace the hard drive to eliminate firmware-level infections.

Reimage the system from a known-good source.

Update the OS and security patches before reconnecting to the network.

The shell script function that could help identify possible network addresses from different source networks belonging to the same company and region is:

function y() { dig $(dig -x $1 | grep PTR | tail -n 1 | awk -F ”.in-addr” ’{print $1}’).origin.asn.cymru.com TXT +short }

This function takes an IP address as an argument and performs two DNS lookups using the dig command. The first lookup uses the -x option to perform a reverse DNS lookup and get the hostname associated with the IP address. The second lookup uses the origin.asn.cymru.com domain to get the autonomous system number (ASN) and other information related to the IP address, such as the country code, registry, or allocation date. The function then prints the IP address and the ASN information, which can help identify any network addresses that belong to the same ASN or region

After recovering a compromised server to its previous state, the analyst should perform forensic analysis to determine the root cause, impact, and scope of the incident, as well as to identify any indicators of compromise, evidence, or artifacts that can be used for further investigation or prosecution. References: CompTIA CySA+ Study Guide: Exam CS0-003, 3rd Edition, Chapter 6, page 244; CompTIA CySA+ CS0-003 Certification Study Guide, Chapter 6, page 253.

Credentialed vulnerability scansallow the scanner tolog into systems and retrieve accurate informationabout installed patches and configurations. If the reportsdo not reflect current patching levels, it is likely that the scan is being performedwithout credentials, leading to incomplete or inaccurate results​.

Option A (Updating the scanning engine)ensures the tool has the latest detection capabilities but does not directly affect scan accuracy for missing patches.

Option B (Centralized patching)helps maintain consistency but does not correct reporting errors.

Option D (Resetting plug-ins)may be useful if plug-ins are outdated, but the primary issue islack of privileged accessduring scanning.

Thus,C is the correct answer, ascredentialed scans provide more accurate vulnerability assessments​.

A tabletop exercise is a type of simulation exercise that involves testing possible incident scenarios and how to react properly, without actually performing any actions or using any resources. A tabletop exercise is usually conducted by a facilitator who presents a realistic scenario to a group of participants, such as a cyberattack, a natural disaster, or a data breach. The participants then discuss and evaluatetheir roles, responsibilities, plans, procedures, and policies for responding to the incident, as well as the potential impacts and outcomes. A tabletop exercise can help identify strengths and weaknesses in the incident response plan, improve communication and coordination among the stakeholders, raise awareness and preparedness for potential incidents, and provide feedback and recommendations for improvement.

Attack simulationsproviderealistic, hands-on scenariosthat mirror true incidents, allowing SOC analysts topractice detection, analysis, and response skillsunder real-world pressure. These simulations are crucial for developing and reinforcing SOC procedures and incident workflows.

Phishing assessments (A)are targeted, limited training.

OpenVAS (B)is a vulnerability scanner, not a training tool.

SOAR (D)is a response automation tool.

Honeypots (E)help observe attacker behavior, but aren't training-focused.

????Reference:

CS0-003 Objectives 3.3 – Incident Response Training

Mya Heath All-in-One – Chapter 14: Post-Incident Activities and Training

In this scenario, the security analyst is presented with multiple vulnerabilities, including a critical zero-day vulnerability affecting the web server with a CVSS score of 10. The CVSS (Common Vulnerability Scoring System) provides a standardized method for rating IT vulnerabilities, with a score of 10 indicating the highest severity.

Option A:Contact the web systems administrator and request that they shut down the asset.

Correct Choice:Given the critical nature of a zero-day vulnerability with a CVSS score of 10, immediate action is warranted to prevent potential exploitation. Shutting down the affected web server reduces the attack surface and mitigates the risk until a patch or workaround is available. This aligns with incident response best practices, where containment is a priority to prevent further damage.

Option B:Monitor the patch releases for all items and escalate patching to the appropriate team.

Incorrect Choice:While monitoring for patches is essential, it is a reactive approach. In the case of a zero-day vulnerability with active exploitation potential, waiting for a patch without implementing immediate protective measures exposes the organization to significant risk.

Option C:Run the vulnerability scan again to verify the presence of the critical finding and the zero-day vulnerability in the environment.

Incorrect Choice:Re-scanning may confirm the vulnerability's presence but does not address the immediate threat. Action to mitigate the risk should take precedence over verification, especially when the vulnerability is known and critical.

Option D:Forward the advisory to the web security team and initiate the prioritization strategy for the other vulnerabilities.

Incorrect Choice:Communicating with the web security team is important; however, in the face of a critical zero-day vulnerability, immediate action (such as shutting down the affected asset) is necessary before addressing other vulnerabilities.

The correct answer is B. Replace the current MD5 with SHA-256.

The vulnerability that the security analyst is able to exploit is a hash collision, which is a situation where two different files produce the same hash value. Hash collisions can allow an attacker to bypass the integrity or authentication checks that rely on hash values, and submit malicious files to the system. The web application uses MD5, which is a hashing algorithm that is known to be vulnerable to hash collisions. Therefore, the analyst should suggest replacing the current MD5 with SHA-256, which is a more secure and collision-resistant hashing algorithm.

The other options are not the best suggestions to mitigate the vulnerability with the fewest changes to the current script and infrastructure. Deploying a WAF (web application firewall) to the front of the application (A) may help protect the web application from some common attacks, but it may not prevent hash collisions or detect malicious files. Deploying an antivirus application on the hosting system © may help scan and remove malicious files from the system, but it may not prevent hash collisions or block malicious files from being submitted. Replacing the MD5 with digital signatures (D)may help verify the authenticity and integrity of the files, but it may require significant changes to the current script and infrastructure, as digital signatures involve public-key cryptography and certificate authorities.

Cloud-specific misconfigurations are security issues that arise from improper or inadequate configuration of cloud resources, such as storage buckets, databases, virtual machines, or containers. Cloud-specific misconfigurations may not be detected by the current scanners that are designed for on-premises environments, as they may not have the visibility or access to the cloud resources or the cloud provider’s APIs. Therefore, one of the implications that should be considered on the new hybrid environment is that cloud-specific misconfigurations may not be detected by the current scanners.

ThePHP script allows remote users to execute system commands via the system() function, meaning an attacker can send arbitrary commands to the server​.

Option A (Cross-site scripting - XSS)is incorrect because this script does not inject JavaScript into a webpage.

Option B (Reverse shell)is possible if an attacker sends a crafted command, but the script itself is more of a general backdoor than a dedicated reverse shell.

Option D (Logic bomb)is incorrect because a logic bomb is typicallytriggered by a specific event or daterather than executing arbitrary commands on demand.

Thus,C (Backdoor attempt) is the best answer, as this scriptgrants unauthorized remote command execution.

Executive management and systems administration are the most likely stakeholders to receive a vulnerability scan report because they are responsible for overseeing the security posture and remediation efforts of the organization. Law enforcement, marketing, legal, and product owner are less likely to be involved in the vulnerability management process or need access to the scan results. References: Cybersecurity Analyst+ - CompTIA, How To Write a Vulnerability Assessment Report | EC-Council, Driving Stakeholder Alignment in Vulnerability Management - LogicGate

The XML file containsJavaScript embedded within a tagthat executes an alert message, which is a commonCross-Site Scripting (XSS)attack vector. The issue occurs becausethe XML schema does not restrict the input to safe characters, allowingarbitrary script executionwhen the XML file is processed by a vulnerable application.

Solution: Implement Input Validation Using an XML Schema Constraint

Option Benforces awhitelist approachby allowingonly alphanumeric characters and spaces([a-zA-Z 0-9]*).

This prevents the inclusion ofmalicious JavaScript or special characterssuch as <, >, or &, which are required for XSS injection​.

Why are the other options incorrect?

Option A: Restricts input to aSocial Security Number (SSN) format ([0-9]{3}-[0-9]{2}-[0-9]{4}). While it prevents JavaScript injection, it is too restrictive and would break legitimate text-based content in the XML.

Option C: Restricts input toonly numeric values ([0-9]*), preventing JavaScript injection but also breaking legitimate non-numeric content in the field.

Option D: Restricts input to asingle positive integer, which does not align with the expected text-based content.

Thus,Option Bis the correct answer, as it enforces proper input validation while still allowing expected text input​.

Dictionary attacks involve an attacker attempting to guess passwords by using a list of common passwords. Implementing a lockout policy is effective because it limits the number of login attempts, thereby hindering the attacker's ability to repeatedly attempt different passwords. Lockout policies are standard in cybersecurity practices to prevent brute-force and dictionary attacks by temporarilydisabling an account after a certain number of failed login attempts. According to CompTIA Security+ standards, password complexity (option B) and multifactor authentication (option A) are helpful but are not as immediately effective in directly preventing repeated attempts as a lockout policy.

This log shows multiple 404 errors being triggered from requests to different directories or paths, which strongly suggests adirectory brute-force attack. In this type of attack, an adversary uses automated tools to enumerate directory or file paths in an attempt to find hidden or misconfigured resources. The frequent 404 “Not Found” HTTP responses from a single IP address attempting to access different URL paths is the signature pattern for directory brute-forcing. This behavior is not consistent with XSS, SQLi, or RCE, which would involve payloads or specific encoded commands, not merely probing paths.

In environments with fragile and legacy equipment, passive scanning is preferred to prevent any potential disruptions that active scanning might cause.

When assessing the security of an Operational Technology (OT) network, especially one with fragile and legacy equipment, it's crucial to use passive instead of active vulnerability scans. Active scanning can sometimes disrupt the operation of sensitive or older equipment. Passive scanning listens to network traffic without sending probing requests, thus minimizing the risk of disruption.

The string provided ispercent-encoded text, commonly used toobfuscate URLs. When decoded, it translates towww.ice-ptic.com. Such encoding is used tobypass email security filtersandspam detectors, making the malicious link appear as benign or unreadable to the automated scanners.

Option Ais incorrect: The string does not match JavaScript shellcode formats.

Option CandDare unlikely and unrelated to the actual behavior.

?Reference:

CySA+ All-in-One Exam Guide by Mya Heath– Chapter 4, Obfuscated Links

CompTIA Exam Objectives: 1.2 – Indicators of Malicious Activity

A rollback had been executed on the instance. If a database server is restored to a previous state, it may reintroduce a vulnerability that was previously fixed. This can happen due to backup and recovery operations, configuration changes, or software updates. A rollback can undo the patching or mitigation actions that were applied to remediate the vulnerability. References: Vulnerability Remediation: It’s Not Just Patching, Section: The Remediation Process; Vulnerability assessment for SQL Server, Section: Remediation

Researching federal laws, regulatory compliance requirements, and organizational policies to document specific reporting SLAs is the best action to address the reporting issue. Reporting SLAs are service level agreements that specify the time frame and the format for notifying the relevant authorities and the affected individuals of a data breach. Reporting SLAs may vary depending on the type and severity of the breach, the type and location of the data, the industry and jurisdiction of the organization, and the internal policies of the organization. By researching and documenting the reporting SLAs for different scenarios, the organization can ensure that it complies with the legal and ethical obligations of data breach notification, and avoid any penalties, fines, or lawsuits that may result from failing to report a breach in a timely and appropriate manner12. References: When and how to report a breach: Data breach reporting best practices, Incident and Breach Management

Updating the system firmware and reimaging the hardware is the best action to perform to remediate the infected device, as it helps to ensure that the device is restored to a clean and secure state and that any traces of malware are removed. Firmware is a type of software that controls the low-level functions of a hardware device, such as a motherboard, hard drive, or network card. Firmware can be updated or flashed to fix bugs, improve performance, or enhance security. Reimaging is a process of erasing and restoring the data on a storage device, such as a hard drive or a solid state drive, using an image file that contains a copy of the operating system, applications, settings, and files. Reimaging can help to recover from system failures, data corruption, or malware infections. Updating the system firmware and reimaging the hardware can help to remediate the infected device by removing any malicious code or configuration changes that may have been made by the malware, as well as restoring any missing or damaged files or settings that may have been affected by the malware. This can help to prevent further damage, data loss, or compromise of the device or the network. The other actions are not as effective or appropriate as updating the system firmware and reimaging the hardware, as they do not address the root cause of the infection or ensure that the device is fully cleaned and secured. Installing an additional malware scanner that will send email alerts to the analyst may help to detect and remove some types of malware, but it may not be able to catch all malware variants or remove them completely. It may also create conflicts or performance issues with other security tools or systems on the device. Configuring the system to use a proxy server for Internet access may help to filter or monitor some types of malicious traffic or requests, but it may not prevent or remove malware that has already infected the device or that uses other methods of communication or propagation. Deleting the user profile and restoring data from backup may help to recover some data or settings that may have been affected by the malware, but it may not remove malware that has infected other parts of the system or that has persisted on the device.

A well-defined timeline of the events is the most important factor to ensure accurate incident response reporting, as it provides a clear and chronological account of what happened, when it happened, who was involved, and what actions were taken. A timeline helps to identify the root cause of the incident, the impact and scope of the damage, the effectiveness of the response, and the lessons learned for future improvement. A timeline also helps to communicate the incident to relevant stakeholders, such as management, legal, regulatory, or media entities. The other factors are also important for incident response reporting, but they are not as essential as a well-defined timeline. Official References:

https://www.ibm.com/topics/incident-response

https://www.crowdstrike.com/cybersecurity-101/incident-response/incident-response-steps/

D (4: HTTPS traffic to an external IP - 5.29.1.5)

The log entry shows an internal system (172.16.1.30) communicating with an external IP (5.29.1.5) overTCP 443 (HTTPS)usingBrowser.exe.

HTTPS traffic to an unknown external IP could indicate data exfiltration, as attackers often use encrypted channels to disguise stolen data transfers.

G (7: FTP traffic to an external backup server - bank.backup.com)

The log entry indicates that an internal machine (172.16.1.25) is transferring data tobank.backup.comusingFTP (port 21)andFileZilla.

FTP is a major concern because it is an outdated, unencrypted protocolthat can be exploited for data exfiltration. If unauthorized, this could be a serious data breach.

Other Options:

A (ARP traffic) → Not a concern(Just address resolution)

B (RPC Kerberos traffic) → Normal for authentication

C (SMB traffic) → Internal file sharing

**E (DNS traffic) → Common, though could be exfiltration in some cases, but not in this log)

F (WUS traffic) → Appears to be Windows Update Service traffic, likely legitimate

Comprehensive and Detailed Step-by-Step Explanation:Performing a vulnerability scan during the recovery phase ensures that corrective actions, such as patches or configuration changes, have effectively addressed the vulnerabilities exploited during the incident. This step validates the system’s security before fully restoring operations.

The first action that should be completed to remediate the findings is to perform proper sanitization on all fields. Sanitization is a process that involves validating, filtering, or encoding any user input or data before processing or storing it on a system or application. Sanitization can help prevent various types of attacks, such as cross-site scripting (XSS), SQL injection, or command injection, that exploit unsanitized input or data to execute malicious scripts, commands, or queries on a system or application. Performing proper sanitization on all fields can help address the most critical and common vulnerability found during the vulnerability assessment, which is XSS.

USB ports are a common attack vector that can be used to deliver malware, steal data, or compromise systems. The first step to mitigate this vulnerability is to check the configurations of the company assets and disable or restrict the USB ports if possible. This will prevent unauthorized devices from being connected and reduce the attack surface. The other options are also important, but they are not the first priority in this scenario.

Mean time to detect (MTTD) is the best metric for an organization to focus on given recent investments in SIEM, SOAR, and a ticketing system. MTTD is a metric that measures how long it takes to detect a security incident or threat from the time it occurs. MTTD can be improved by using tools and processes that can collect, correlate, analyze, and alert on security data from various sources. SIEM, SOAR, and ticketing systems are examples of such tools and processes that can help reduce MTTD and enhance security operations. Official References: https://www.eccouncil.org/cybersecurity-exchange/threat-intelligence/cyber-kill-chain-seven-steps-cyberattack

USB ports are a common attack vector that can be used to deliver malware, steal data, or compromise systems. The first step to mitigate this vulnerability is to check the configurations of the company assets and disable or restrict the USB ports if possible. This will prevent unauthorized devices from being connected and reduce the attack surface. The other options are also important, but they are not the first priority in this scenario.

Automation is the best concept to describe the example, as it reflects the use of technology to perform tasks or processes without human intervention. Automation can help to improve efficiency, accuracy, consistency, and scalability of various operations, such as identity and access management (IAM). IAM is a security framework that enables organizations to manage the identities and access rights of users and devices across different systems and applications. IAM can help to ensure that only authorized users and devices can access the appropriate resources at the appropriate time and for the appropriate purpose. IAM can involve various tasks or processes, such as authentication, authorization, provisioning, deprovisioning, auditing, or reporting. Automation can help to simplify and streamline these tasks or processes by using software tools or scripts that can execute predefined actions or workflows based on certain triggers or conditions. For example, automation can help to create, update, or delete user accounts in bulk based on a file or a database, rather than manually entering or modifying each account individually. The example in the question shows that an API is used to insert bulk access requests from a file into an identity management system. An API (Application Programming Interface) is a set of rules or specifications that defines how different software components or systems can communicate and exchange data with each other. An API can help to enable automation by providing a standardized and consistent way to access and manipulate data or functionality of a software component or system. The example in the question shows that an API is used to automate the process of inserting bulk access requests from a file into an identity management system, rather than manually entering each request one by one. The other options are not correct, as they describe different concepts or techniques. Command and control is a term that refers to the ability of an attacker to remotely control a compromised system or device, such as using malware or backdoors. Command and control is not related to what is described in the example. Data enrichment is a term that refers to the process of enhancing or augmenting existing data with additional information from external sources, such as adding demographic or behavioral attributes to customer profiles. Data enrichment is not related to what is described in the example. Single sign-on is a term that refers to an authentication method thatallows users to access multiple systems or applications with one set of credentials, such as using a single username and password for different websites or services. Single sign-on is not related to what is described in the example.

The correct answer is C. False negative.

A false negative is a situation where an attack or a threat is not detected by a security control, even though it should have been. In this case, the SIEM rule was unable to detect an attack with nine failed logins, which is below the threshold of ten failed logins that triggers an alert. This means that the SIEM rule missed a potential attack and failed to alert the security analysts, resulting in a false negative.

A false positive is a situation where a benign or normal activity is detected as an attack or a threat by a security control, even though it is not. A true negative is a situation where a benign or normal activity is not detected as an attack or a threat by a security control, as expected. A true positive is a situation where an attack or a threat is detected by a security control, as expected. These are not the correct answers for this question.

The best practice that the company should follow with this proxy is to decommission the proxy. Decommissioning the proxy involves removing or disposing of the proxy from the rack and the network, as well as deleting or wiping any data or configuration on the proxy. Decommissioning the proxy can help eliminate the vulnerability on the proxy, as well as reduce the attack surface, complexity, or cost of maintaining the network. Decommissioning the proxy can also free up space or resources for other devices or systems that are in use or needed by the company.

In this scenario, adding the IP address to the EDR (Endpoint Detection and Response) deny list is an immediate and effective way to block further reconnaissance activities from the malicious source. EDR solutions are designed to provide advanced endpoint security, including blocking specific IP addresses and preventing potentially harmful traffic. This proactive step aligns with CompTIA Cybersecurity Analyst (CySA+) best practices for threat prevention and response. While other options, such as using SIEM for monitoring (option B) or WAF policies (option C), provide additional layers of security, they do not directly block the threat in the same immediate way that adding the IP to the EDR deny list does.

The most likely scenario occurring with the time stamps is that the NTP server is not configured on the host. NTP is the Network Time Protocol, which is used to synchronize the clocks of computers over a network. NTP uses a hierarchical system of time sources, where each level is assigned a stratum number. The most accurate time sources, such as atomic clocks or GPS receivers, are at stratum 0, and the devices that synchronize with them are at stratum 1, and so on. NTP clients can query multiple NTP servers and use algorithms to select the best time source and adjust their clocks accordingly1. If the NTP server is not configured on the host, the host will rely on its own hardware clock, which may drift over time and become inaccurate. This can cause discrepancies in the time stamps between the host and other devices on the network, such as the firewall, which may be synchronized with a different NTP server or use a different time zone. This can affect the security analysis and correlation of events, as well as the compliance and auditing of the network23. References: How the Windows Time Service Works, Time Synchronization - All You Need To Know, Firewall rules logging: a closer look at our new network compliance and …

A cloud access security broker (CASB) is a tool that can help reduce the risk of shadow IT in the enterprise by providing visibility and control over cloud applications and services. A CASB can enable policy enforcement by blocking unauthorized or risky cloud applications, enforcing data loss prevention rules, encrypting sensitive data, and detecting anomalous user behavior.

Comprehensive and Detailed Explanation From Exact Extract:

To determine which system to remediate first using only CVSS vectors, the analyst should prioritize the vulnerability that is most severe and most easily exploitable, especially when it is exploitable over the network and requires no privileges and no user interaction.

The Web server has the most dangerous combination of exploitability and impact:

Attack Vector = Network (AV:N) → exploitable remotely over a network

Attack Complexity = Low (AC:L) → no special conditions required

Privileges Required = None (PR:N) → attacker doesn’t need credentials

User Interaction = None (UI:N) → no user action required

Impact = High for Confidentiality, Integrity, and Availability (C:H / I:H / A:H) → full compromise potential

The Sybex CySA+ Study Guide explains that CVSS provides a 0–10 severity score and that analysts must be able to interpret key metrics like Attack Vector, Attack Complexity, Privileges Required, User Interaction, and Impact.

The All-in-One guide defines Attack Vector and notes that the more remote the vector, the higher the score (Network is remotely exploitable).

And Secbay Press states that organizations use CVSS as a basis for prioritization, typically addressing higher scores first.

Exact extract (Secbay Press): “Organizations often use CVSS scores as a basis for prioritizing vulnerabilities, addressing those with higher scores first.”

Why the other assets are lower priority than the Web server (based on the vectors)

File server (AV:L) is local attack vector, meaning the attacker must already have local access; that generally reduces priority compared to a remotely exploitable (AV:N) issue. (Attack vector definitions and scoring emphasize Network vs Local distinctions.)

Mail server (AC:H) requires high attack complexity, lowering exploitability compared to the Web server’s AC:L.

Domain controller (PR:R, UI:R) requires privileges and user interaction, which lowers exploitability compared to PR:N/UI:N on the Web server.

Bottom line: The Web server is the most immediately dangerous because it is remotely exploitable (AV:N) with low complexity (AC:L), requires no privileges (PR:N) and no user interaction (UI:N), and has high impact across C/I/A—making it the strongest candidate for first remediation under CVSS-based prioritization.

References (CompTIA CySA+ CS0-003 documents / study guides used):

Secbay Press, CompTIA CySA+ Exam Prep Guide (CS0-003): CVSS used to prioritize; higher scores addressed first

Mike Chapple & David Seidl, CompTIA CySA+ Study Guide (CS0-003): CVSS metrics and interpretation (AV/AC/PR/UI/Impact) and severity score concept

Mya Heath et al., CompTIA CySA+ All-in-One Exam Guide (CS0-003): Attack Vector/Attack Complexity definitions; remote vectors score higher

The correct answer is A. Configure the server to prefer TLS 1.3 and B. Remove cipher suites that use CBC.

A padding oracle attack is a type of attack that exploits the padding validation of a cryptographic message to decrypt the ciphertext without knowing the key. A padding oracle is a system that responds to queries about whether a message has a valid padding or not, such as a web server that returns different error messages for invalid padding or invalid MAC. A padding oracle attack can be applied to the CBC mode of operation, where the attacker can manipulate the ciphertext blocks and use the oracle’s responses to recover the plaintext12.

To remediate this issue, the organization should make the following configuration changes:

Configure the server to prefer TLS 1.3. TLS 1.3 is the latest version of the Transport Layer Security protocol, which provides secure communication between clients and servers. TLS 1.3 has several security improvements over previous versions, such as:

It deprecates weak and obsolete cryptographic algorithms, such as RC4, MD5, SHA-1, DES, 3DES, and CBC mode.

It supports only strong and modern cryptographic algorithms, such as AES-GCM, ChaCha20-Poly1305, and SHA-256/384.

It reduces the number of round trips required for the handshake protocol, which improves performance and latency.

It encrypts more parts of the handshake protocol, which enhances privacy and confidentiality.

It introduces a zero round-trip time (0-RTT) mode, which allows resuming previous sessions without additional round trips.

It supports forward secrecy by default, which means that compromising the long-term keys does not affect the security of past sessions3456.

Remove cipher suites that use CBC. Cipher suites are combinations of cryptographic algorithms that specify how TLS connections are secured. Cipher suites that use CBC mode are vulnerable to padding oracle attacks, as well as other attacks such as BEAST and Lucky 13. Therefore, they should be removed from the server’s configuration and replaced with cipher suites that use more secure modes of operation, such as GCM or CCM78.

The other options are not effective or necessary to remediate this issue.

Option C is not effective because configuring the server to prefer ephemeral modes for key exchange does not prevent padding oracle attacks. Ephemeral modes for key exchange are methods that generate temporary and random keys for each session, such as Diffie-Hellman or Elliptic Curve Diffie-Hellman. Ephemeral modes provide forward secrecy, which means that compromising the long-term keys does not affect the security of past sessions. However, ephemeral modes do not protect against padding oracle attacks, which exploit the padding validation of the ciphertext rather than the key exchange9.

Option D is not necessary because requiring client browsers to present a user certificate for mutual authentication does not prevent padding oracle attacks. Mutual authentication is a process that verifies the identity of both parties in a communication, such as using certificates or passwords. Mutual authentication enhances security by preventing impersonation or spoofing attacks. However, mutual authentication does not protect against padding oracle attacks, which exploit the padding validation of the ciphertext rather than the authentication.

Option E is not necessary because configuring the server to require HSTS does not prevent padding oracle attacks. HSTS stands for HTTP Strict Transport Security and it is a mechanism that forces browsers to use HTTPS connections instead of HTTP connections when communicating with a web server. HSTS enhances security by preventing downgrade or man-in-the-middle attacks that try to intercept or modify HTTP traffic. However, HSTS does not protect against padding oracle attacks, which exploit the padding validation of HTTPS traffic rather than the protocol.

Option F is not effective because removing cipher suites that use GCM does not prevent padding oracle attacks. GCM stands for Galois/Counter Mode and it is a mode of operation that provides both encryption and authentication for block ciphers, such as AES. GCM is more secure and efficient thanCBC mode, as it prevents various types of attacks, such as padding oracle, BEAST, Lucky 13, and IV reuse attacks. Therefore, removing cipher suites that use GCM would reduce security rather than enhance it .

Deploying EDR on the web server and the database server to reduce the adversaries capabilities and using micro segmentation to restrict connectivity to/from the web and database servers are two compensating controls that will help contain the adversary while meeting the other requirements. A compensating control is a security measure that is implemented to mitigate the risk of a vulnerability or an attack when the primary control is not feasible or effective. EDR stands for Endpoint Detection and Response, which is a tool that monitors endpoints for malicious activity and provides automated or manual response capabilities. EDR can help contain the adversary by detecting and blocking their actions, such as data exfiltration, lateral movement, privilege escalation, or command execution. Micro segmentation is a technique that divides a network into smaller segments based on policies and rules, and applies granular access controls to each segment. Micro segmentation can help contain the adversary by isolating the web and database servers from other parts of the network, and limiting the traffic that can flow between them. Official References:

https://partners.comptia.org/docs/default-source/resources/comptia-cysa-cs0-002-exam-objectives

https://www.comptia.org/certifications/cybersecurity-analyst

https://www.comptia.org/blog/the-new-comptia-cybersecurity-analyst-your-questions-answered

Single Sign-On (SSO) allows users to authenticate once and gain access to multiple applications without needing to re-enter credentials for each one.

It reduces password fatigue, improves security, and streamlines authentication across vendor portals.

Why Not Other Options?

A (API) → APIs facilitate data exchange but do not solve authentication problems.

B (MFA) → Enhances security but still requires multiple logins.

D (VPN) → Secures connections but does not eliminate multiple logins.

A risk score is a numerical value that represents the potential impact and likelihood of a vulnerability being exploited. It can help to identify the potential loss incurred by an issue and prioritize remediation efforts accordingly. https://www.comptia.org/training/books/cysa-cs0-003-study-guide

JavaScript Object Notation (JSON) is commonly used for transmitting data in web applications and would be suitable for updating dashboards that integrate various data sources. It's lightweight and easy to parse and generate.

Thelessons learnedphase is a formal step in the incident response process where teamsreview what went wrong, what worked, and how to improvefuture responses. Management uses this toadjust policies, procedures, and controlsbased on real incident experiences.

Tabletop (A)is a simulated discussion, not post-incident.

Root cause analysis (C)finds technical origins but doesn’t focus on process improvement.

Forensics (D)supports investigation but not process revision.

????Reference:

CS0-003 Domain 3.0 – Post-Incident Activities

Chapple & Seidl – Study Guide, Chapter 11: Containment and Recovery

A credentialed scan is a type of vulnerability scan that uses valid credentials to log in to the scanned systems and perform a more thorough and accurate assessment of their vulnerabilities. A credentialed scan can access more information than a non-credentialed scan, such as registry keys, patch levels, configuration settings, and installed applications. A credentialed scan can also reduce the number of false positives and false negatives, as it can verify the actual state of the system rather than relying on inference or assumptions. The other types of scans are not related to the issue of incomplete findings, as they refer to different aspects of vulnerability scanning, such as the scope, location, or frequency of the scan. An external scan is a scan that is performed from outside the network perimeter, usually from the internet. An external scan can reveal how an attacker would see the network and what vulnerabilities are exposed to the public. An external scan cannot access internal systems or resources that are behind firewalls or other security controls. A differential scan is a scan that compares the results of two scans and highlights the differences between them. A differential scan can help identify changes in the network environment, such as new vulnerabilities, patched vulnerabilities, or new devices. A differential scan does not provide a complete list of findings by itself, but rather a summary of changes. A network scan is a scan that focuses on the network layer of the OSI model and detects vulnerabilities related to network devices, protocols, services, and configurations. A network scan candiscover open ports, misconfigured firewalls, unencrypted traffic, and other network-related issues. A network scan does not provide information about the application layer or the host layer of the OSI model, such as web applications or operating systems.

Comprehensive Detailed Explanation:The nmap scan results show that Telnet (port 23) is open. Telnet transmits data, including credentials, in plaintext, which is insecure and should be disabled to enhance security. Here’s an explanation of each option:

A. Disable all protocols that do not use encryption

Explanation: Disabling unencrypted protocols (such as Telnet) reduces exposure to man-in-the-middle (MITM) attacks and credential sniffing. Telnet should be replaced with a secure protocol like SSH, which provides encryption for transmitted data.

B. Configure client certificates for domain services

Explanation: While client certificates enhance authentication security, they are more relevant to services like LDAP over SSL (port 636), which is already secure. This would not address the Telnet vulnerability.

C. Ensure that this system is behind a NGFW

Explanation: A Next-Generation Firewall (NGFW) provides enhanced network security, but it may not mitigate the risks of unencrypted protocols if they are allowed internally.

D. Deploy a publicly trusted root CA for secure websites

Explanation: Public root CAs are used for website authentication and encryption, relevant only if this system is hosting a publicly accessible HTTPS service. It would not impact Telnet security.