CAS-005 Questions and Answers

User behavior analytics (UBA)detectsanomalousactivityby analyzing historical patterns and comparing them to recent behavior. The time shift in account activity suggestspotential compromise or misuse.

TTP-based inquiries (A)focus on known attack tactics, techniques, and procedures but do not involve behavior tracking.

Adversary emulation (C)simulates attacks but does not analyze real data trends.

OSINT analysis (D)gathers intelligence from public sources, which is unrelated to internal account behavior analysis.

The key requirement is toinstantly eliminate data losson a lost device.

Cryptographic erasureworks by deleting encryption keys used for FDE (full disk encryption), rendering all data unrecoverable within seconds — satisfying the "mitigate within seconds" requirement.

Revoking certificates won’t wipe the data from a lost tablet.

Changing MFA credentials won’t help unless the device is secured, and app allow lists don’t apply post-loss.

FromCAS-005, Domain 3: Secure Systems Design and Deployment:

“Cryptographic erase (CE) renders data irrecoverable by deleting encryption keys used to protect data on the device.”

Matching Relevant Findings to the Affected Hosts:

Finding 1:

Affected Host: DNS

Reason: Users are unable to log into the domain from their workstations after relocating to Site B, which implies a failure in domain name services that are critical for user authentication and domain login.

Finding 2:

Affected Host: Pumps

Reason: Thepump room at Site B becoming inoperable directly points to the critical infrastructure components associated with pumping operations.

Finding 3:

Affected Host: VPN Concentrator

Reason: Unreliable internet connectivity at Site B due to route flapping indicates issues with network routing, which is often managed by VPN concentrators that handle site-to-site connectivity.

Corrective Actions for Finding 3:

Finding 3 Corrective Action:

Action: Modify the BGP configuration

Reason: Route flapping is often related to issues with Border Gateway Protocol (BGP) configurations. Adjusting BGP settings can stabilize routes and improve internet connectivity reliability.

Replication to Site B for Finding 1:

Affected Host: DNS

Domain Name System (DNS) services are essential for translating domain names into IP addresses, allowing users to log into the network. Replicating DNS services ensures that even if Site A is disrupted, users at Site B can still authenticate and access necessary resources.

Replication to Site B for Finding 2:

Affected Host: Pumps

The operation of the pump room is crucial for maintaining various functions within the infrastructure. Replicating the control systems and configurations for the pumps at Site B ensures that operations can continue smoothly even if Site A is affected.

Configuration Changes for Finding 3:

Affected Host: VPN Concentrator

Route flapping is a situation where routes become unstable, causing frequent changes in the best path for data to travel. This instability can be mitigated by modifying BGP configurations to ensure more stable routing. VPN concentrators, which manage connections between sites, are typically configured with BGP for optimal routing.

To reduce the number of failed patch deployments, the systems administrator should implement a robust change management process. Change management ensures that all modifications to systems or applications are planned, tested, and approved before deployment. This systematic approach reduces the risk of unplanned changes that can cause patch failures and ensures that patches are deployed in a controlled and predictable manner.

Comprehensive and Detailed Explanation:

DomainKeys Identified Mail (DKIM) digitally signs outbound messages with the organization’s private key, enabling recipients to verify integrity and authenticity using the corresponding public key in DNS.

SPF validates sending server IPs, not message integrity.

DMARC builds policy enforcement on top of SPF and DKIM results.

TLS secures the transport channel, not the message content itself.

Enabling dashboards for service status monitoring is the best action to support rapid incident response. The table shows various services with different risk, criticality, and alert severity ratings. To ensure timely and effective incident response, real-time visibility into the status of these services is crucial.

Why Dashboards for Service Status Monitoring?

Real-time Visibility: Dashboards provide an at-a-glance view of the current status of all critical services, enabling rapid detection of issues.

CentralizedMonitoring: A single platform to monitor the status of multiple services helps streamline incident response efforts.

Proactive Alerting: Dashboards can be configured to show alerts and anomalies immediately, ensuring that incidents are addressed as soon as they arise.

Improved Decision Making: Real-time data helps incident response teams make informed decisions quickly, reducing downtime and mitigating impact.

Other options, while useful, do not offer the same level of comprehensive, real-time visibility and proactive alerting:

A. Automate alerting to IT support for phone system outages: This addresses one service but does not provide a holistic view.

C. Send emails for failed log-in attempts on the public website: This is a specific alert for one type of issue and does not cover all services.

D. Configure automated isolation of human resources systems: This is a reactive measure for a specific service and does not provide real-time status monitoring.

The hijacked administrator account was used across multiple ASNs (indicating different network locations) in a short time, despite MFA and SSO. This suggests a stolen session or token misuse. Let’s analyze:

A. Token theft detection with lockouts:Useful for detecting stolen SSO tokens, but it’s reactive and may not prevent initial misuse across networks.

B. Context-based authentication:This adds real-time checks (e.g., geolocation, IP changes) to verify login attempts. Given the rapid ASN changes, this proactively mitigates the issue by challenging suspicious logins, aligning with CAS-005’s focus on adaptive security.

C. Decentralize accounts:This removes SSO, increasing complexity and weakening MFA enforcement, which isn’t practical or secure.

The log shows an AXFR (zone transfer) query, which exposed internal DNS records, aiding lateral movement. Let’s evaluate:

A. Disabling DNS zone transfers:AXFR allows full DNS zone data to be transferred. Disabling it externally prevents attackers from mapping internal networks, directly mitigating this issue per CAS-005’s security operations focus.

B. Restricting to UDP/53:AXFR uses TCP/53, so this wouldn’t stop it.

C. DNSmasking:Obscures records but isn’t a standard term for this fix.

The application allows users to input URLs, which the application then fetches using requests.get(url). This functionality can be exploited if not properly validated, leading to potential security vulnerabilities such as Server-Side Request Forgery (SSRF).

Implementing a code scanner as part of the development pipeline can help identify insecure coding practices, such as unsanitized user inputs and improper handling of external requests. Code scanners analyze the source code for known vulnerabilities and coding errors, enabling developers to remediate issues before deployment.

Based on the security policy that any publicly available server must be patched within 12 hours after a patch is released, the securityanalyst should patch Host 1 first. Here’s why:

Public Availability: Host 1 is externally available, making it accessible from the internet. Publicly available servers are at higher risk of being targeted by attackers, especially when a zero-day vulnerability is known.

Exposure to Threats: Host 1 has IIS installed and is publicly accessible, increasing its exposure to potential exploitation. Patching this host first reduces the risk of a successful attack.

Prioritization of Critical Assets: According to best practices, assets that are exposed to higher risks should be prioritized for patching to mitigate potential threats promptly.

The technique that best addresses the issue of insider threats from employees who have individual access to encrypted material is key splitting. Here’s why:

Key Splitting: Key splitting involves dividing a cryptographic key into multiple parts anddistributing these parts among different individuals or systems. This ensures that no single individual has complete access to the key, thereby mitigating the risk of insider threats.

Increased Security: By requiring multiple parties to combine their key parts to access encrypted material, key splitting provides an additional layer of security. This approach is particularly useful in environments where sensitive data needs to be protected from unauthorized access by insiders.

Compliance and Best Practices: Key splitting aligns with best practices and regulatory requirements for handling sensitive information, ensuring that access is tightly controlled and monitored.

Step-by-Step Explanation:

Runtime Application Self-Protection (RASP) (A)monitors and protects applications in real time by detecting and blocking attacks as they occur. Unlike traditional security solutions, RASP is integrated into the application itself, meaning it works regardless of the programming language used. It effectively mitigates common vulnerabilities such as SQL injection, XSS, and buffer overflows.

Dynamic Application Security Testing (DAST) (C) is a passive scanning approach that may not prevent attacks in real-time, while Network Intrusion PreventionSystems (NIPS) (D) focuses on network traffic, not application-layer security.

The question states that security scanning and quality assurance (QA) in the CI/CD pipeline have been completed with no issues, indicating that the code in the test branch is ready for production. According to the CompTIA SecurityX CAS-005 study guide (Domain 2: Security Operations, 2.3), in a secure CI/CD pipeline, once code passes automated security scans, QA, and other checks (e.g., unit testing, peer reviews), the next step is to merge the tested branch into the main branch for deployment to production.

Option B:Threat modeling is typically performed earlier, during design or development, not after passing CI/CD checks.

Option C:Unit testing is part of the CI/CD pipeline and should already be completed.

Option D:Peer reviews are conducted before or during the test phase, not after QAand security scans are clear.

Option A:Merging the test branch to the main branch is the logical next step to prepare for production deployment.

Creating a separate network for users who need access tothe application is the best action to secure an internal application that is critical to the production area and cannot be updated.

Why Separate Network?

Network Segmentation: Isolates the critical application from the rest of the network, reducing the risk of compromise and limiting the potential impact of any security incidents.

Controlled Access: Ensures that only authorized users have access to the application, enhancing security and reducing the attack surface.

Minimized Risk: Segmentation helps in protecting the application from vulnerabilities that could be exploited from other parts of the network.

Other options, while beneficial, do not provide the same level of security for a critical application:

A. Disallow wireless access: Useful but does not provide comprehensive protection.

B. Deploy intrusion detection capabilities using a network tap: Enhances monitoring but does not provide the same level of isolation and control.

C. Create an acceptable use policy: Important for governance but does not provide technical security controls.

The log-in activity indicates a security threat, particularly involving the ADMIN account with a high-risk failure status. This suggests that the account may be targeted by malicious activities such as credential stuffing or brute force attacks.

Updating log configuration settings (A) may help in better logging future activities but does not address the immediate threat.

Changing the admin account password (B) is a good practice but may not fully mitigate the ongoing threat if the account has already been compromised.

Blocking employees (C) from logging into non-business applications might help in reducing attack surfaces but doesn't directly address the compromised account issue.

Implementing automation to disable accounts associated with high-risk activities ensures an immediate response to the detected threat, preventing further unauthorized access and allowing time for thorough investigation and remediation.

Risk mitigation involves taking actions to reduce either the likelihood or impact of a threat. By implementing a firewall between the two environments, Company A is minimizing the risk of threats from Company B impacting its own systems. Accepting the risk would involve taking no action, avoiding it would mean terminating activities with Company B, and transferring would involve outsourcing the risk, none of which occurred here.

Reviewing data sovereignty laws in countries where the organization has no presence is likely due to concerns about regulatory enforcement. Data sovereignty laws dictate how data can be stored, processed, and transferred across borders. Understanding these laws is crucial for compliance, especially if the organization handles data that may be subject to foreign regulations.

A. The organization is performing due diligence of potential tax issues: This is less likely as tax issues are generally not directly related to data sovereignty laws.

B. The organization has been subject to legal proceedings in countries where it has a presence: While possible, this does not explain the focus on countries where the organization has no presence.

C. The organization is concerned with new regulatory enforcement in other countries: This is the most likely reason. New regulations could impact the organization’s operations, especially if they involve data transfers or processing data from these countries.

D. The organization has suffered brand reputation damage from incorrect media coverage: This is less relevant to the need for reviewing data sovereignty laws.

Integrating IDS, firewall, and DLP to reduce response time requires orchestration and automation. Let’s evaluate:

A. SOAR(Security Orchestration, Automation, and Response):SOAR integrates security tools, automates workflows, and speeds up incident response. It’s the best fit for this scenario, as CAS-005 highlights SOAR for operational efficiency.

B. CWPP (CloudWorkload Protection Platform):Focused on securing cloud workloads, not integrating on-premises tools.

C. XCCDF (Extensible Configuration Checklist Description Format):A standard for compliance checklists, not a tool for integration or response.

Static Application Security Testing (SAST) involves analyzing source code or compiled code for security vulnerabilities without executing the program. This method is well-suited for identifying syntax errors, coding standards violations, and potential security issues early in the development lifecycle.

A. Static application security testing (SAST): SAST tools analyze the source code to detect syntax errors, vulnerabilities, and other issues before the code is run. This is the most relevant task for the DevSecOps team to identify syntax errors and improve code quality.

B. Software composition analysis: This focuses on identifying vulnerabilities in open-source components and libraries used in the application but does not address syntax errors directly.

C. Runtime application self-protection (RASP): RASP involves monitoring and protecting applications during runtime, which does not help in identifying syntax errors during the development phase.

D. Web application vulnerability scanning: This involves scanning the running application for vulnerabilities but does not address syntax errors in the code.

To secure the Operational Technology (OT) environment based on the given requirements, the best approach is to implement a bastion host inthe OT network. The bastion host serves as a secure entry point for remote access, allowing third-party vendors to connect while being monitored by security tools. Using a dedicated update server for workstations ensures that security updates are applied in a controlled manner without direct internet access.

Excessive MFA push notifications can be a sign of an attempted push notification attack, where attackers repeatedly send MFA prompts hoping the user will eventually approve one by mistake. To mitigate this:

A. Provisioning FIDO2 devices: While FIDO2 devices offer strong authentication, they may not be practical for all users and do not directly address the issue of excessive push notifications.

B. Deploying a text message-based MFA: SMS-based MFA can still be vulnerable to similar spamming attacks and phishing.

C. Enabling OTP via email: Email-based OTPs add another layer of security but do not directly solve the issue of excessive notifications.

D. Configuring prompt-driven MFA: This option allows users to respond to prompts in a secure manner, often including features like time-limited approval windows, additional verification steps, or requiring specificactions to approve. This can help prevent users from accidentally approving malicious attempts.

Configuring prompt-driven MFA is the best solution to restrict unnecessary MFA notifications and improve security.

Based on the provided logs, the user has accessed various applications from different geographic locations within a very short timeframe. This pattern is indicative of the "impossible travel" security rule, a common feature in Single Sign-On (SSO) systems designed to detect and prevent fraudulent access attempts.

Analysis of Logs:

At 8:47 p.m., the user accessed a VPN from Toronto.

At 8:48 p.m., the user accessed email from Los Angeles.

At 8:48 p.m., the user accessed the human resources system from Los Angeles.

At 8:49 p.m., the user accessed email again from Los Angeles.

At 8:52 p.m., the user attempted to access the human resources system from Toronto, which was denied.

These rapid changes in location are physically impossible and typically trigger security measures to prevent unauthorized access. The SSO system detected these inconsistencies and likely flagged the activity as suspicious, resulting in access denial.

Understanding the Security Event:

Unauthorized usersgained access from non-production to production.

IAM policies were weak, allowingbulk user creation.

Vulnerability assessments were disabled, andpatching was delayed.

Logs were unavailable, making incident response difficult.

Why Options A, D, and E areCorrect:

A (Disable bulk user creation by IAM team)→ Prevents unauthorized mass user account creation, which could beexploited by attackers.

D (Routine updates for endpoints & network devices)→ Patch management ensuresvulnerabilities are not left open for attackers.

E (Ensure all security/network devices send logs to SIEM)→ Helps withreal-time monitoring and detection of unauthorized activities.

Why Other Options Are Incorrect:

B (180-day log retention)→ While log retention is good,real-time monitoring is the priority.

C (Review application allow list daily)→ Reviewing itdaily is impractical. Regular audits are better.

F (Restrict production-to-non-production traffic)→ The issue isunauthorized access, not traffic routing.

The table shows that the user "SALES1" is consistently blocked despite having met the MFA requirements. The common factor in these blocked attempts is the source IP address (8.11.4.16) being identified as from Germany while the user is assigned to France. This discrepancy suggests that the network geolocation is being misidentified by the authentication server, causing legitimate access attempts to be blocked.

Why Network Geolocation Misidentification?

Geolocation Accuracy: Authentication systems often use IP geolocation to verify the location of access attempts. Incorrect geolocation data can lead to legitimate requests being denied if they appear to come from unexpected locations.

Security Policies: Company security policies might block access attempts from certain locations to prevent unauthorized access. If the geolocation is wrong, legitimate users can be inadvertently blocked.

Consistent Pattern: The user "SALES1" from the IP address 8.11.4.16 is always blocked, indicating a consistent issue with geolocation.

Other options do not align with the pattern observed:

A. Bypass MFA requirements: MFA is satisfied, so bypassing MFA is not the issue.

C. Administrator access policy: This is about user access, not specific administrator access.

D. OTP codes: The user has satisfied MFA, so OTP code configuration is not the issue.

Comprehensive and Detailed Explanation:

In a Discretionary Access Control (DAC) model, the data owner or an assigned stakeholder has the authority to determine who can access resources. SecurityX CAS-005 IAM objectives describe DAC as user- or owner-controlled, where permissions can be granted or revoked at the owner’s discretion.

In this scenario, because permissions from the legacy system could not be migrated, multiple stakeholders were made responsible for assigning and managing access—matching the DAC model’s characteristics.

Option A relates to outsourcing, which does not define an access control model.

Option C is about authentication limitations, unrelated to the choice of DAC.

Option D describes backup responsibilities, which are operational tasks, not access control.

A Cloud Access Security Broker (CASB) is a security policy enforcement point placed between cloud service consumers and cloud service providers to combine and interject enterprise security policies as cloud-based resources are accessed. Implementing a CASB provides several benefits:

A. Improve firewall rules to avoid access to those platforms: This can help but is not as effective or comprehensive as a CASB.

B. Implement a cloud-access security broker: A CASB can provide visibility into cloud application usage, enforce data security policies, and protect against data leaks by monitoring and controlling access to cloud services. It also provides advanced features like data encryption, data loss prevention (DLP), and compliance monitoring.

C. Create SIEM rules to raise alerts for access to those platforms: This helps in monitoring but does not prevent data leaks.

D. Deploy an internet proxy that filters certain domains: This can block access to specific sites but lacks the granular control and visibility provided by a CASB.

Implementing a CASB is the most comprehensive solution to decrease the risk of data leaks by providing visibility, control, and enforcement of security policies for cloud services.

For SSDs,incinerationis considered the most secure method of physical destruction, ensuring no data remanence. SSDs store data differently compared to traditional spinning disks, making degaussing ineffective. Overwriting and formatting may not reliably erase all storage cells due to wear-leveling technologies. Shredding may work if the granularity is extremely fine, but incineration guarantees complete destruction beyond recovery.

To improve the quality of code scanning results and reduce false positives, the best solution is to limit the tool to a specific coding language and fine-tune the rule set. By configuring the code scanning tool to focus on the specific language used in the application, the tool can more accurately identify relevant issues and reduce the number of false positives. Additionally, tuning the rule set ensures that the tool's checks are appropriate for the application's context, further improving the accuracy ofthe scan results.

Preparing communication templates that have been vetted by both internal and external counsel ensures that the organization can respond quickly and effectively to internal and external inquiries, comply with regulatory requirements, and provide transparency in the event of a breach.

Why Communication Templates?

Timely Response: Pre-prepared templates ensure that responses are ready to be deployed quickly, reducing response time.

Regulatory Compliance: Templates vetted by counsel ensure that all communications meet legal and regulatory requirements.

Consistent Messaging: Ensures that all responses are consistent, clear, and accurate, maintaining the organization’s credibility.

Crisis Management: Pre-prepared templates are a critical component of a broader crisis management plan, ensuring that all stakeholders are informed appropriately.

Other options, while useful, do not provide the same level of preparedness and compliance:

A. Outsourcing to an external consultant: This may delay response times and lose internal control over the communication.

B. Integrating automated response mechanisms: Useful for efficiency but not for ensuring compliant and vetted responses.

D. Conducting lessons-learned activities: Important for improving processes but does not provide immediate preparedness for communication.

In the context of establishing a Security Operations Center (SOC) with a threat-modeling function, it's crucial to understand how data flows within the organization's systems. Network and data flow diagrams provide a visual representation of the system's architecture, illustrating how data moves between components, which is essential for identifying potential security weaknesses and antipatterns. Antipatterns are common responses to recurring problems that are ineffective and risk-inducing. By analyzing these diagrams, the consultant can pinpoint areas where security controls may be lacking or misconfigured, thereby facilitating the development of effective threat models.​

While other options like unpatchable IoT devices (Option B) and inventories of cloud resources (Option E) are important for comprehensive security assessments, they are more pertinent during later stages, such as vulnerability management and asset inventory. The initial phase of threat modeling focuses on understanding the system's structure and data flows to identify potential threats, making network and data flow diagrams the most critical information at this stage.​

RACI matrix(Responsible, Accountable, Consulted, Informed) is used for role mapping across the project lifecycle.

CMDB is a configuration inventory; ITIL is a framework. Recall trees are for disaster recovery/business continuity.

FromCAS-005, Domain 1: Security Governance and Compliance:

“The RACI matrix is essential in role assignment and accountability for software development and operational processes.”

Dynamic Application Security Testing (DAST) is crucial for identifying and addressing security vulnerabilities during the software development life cycle (SDLC). Ensuring that DAST scans are routinely scheduled helps in maintaining a secure development process.

Why Routine DAST Scans?

Continuous Security Assessment: Regular DAST scans help in identifying vulnerabilities in real-time, ensuring they are addressed promptly.

Compliance: Routine scans ensure that the development process complies with security standards and regulations.

Proactive Threat Mitigation: Regular scans help in early detection and mitigation of potential security threats, reducing the risk of breaches.

Integration into SDLC: Ensures security is embedded within the development process, promoting a security-first approach.

Other options, while relevant, do not directly address the continuous assessment and proactive identification of threats:

A. If developers are unable to promote to production: This is more of an operational issue than a security assessment.

B. If DAST code is being stored to a single code repository: This concerns code management rather than security testing frequency.

D. If role-based training is deployed: While important, training alone does not ensure continuous security assessment.

The Common Vulnerability Scoring System (CVSS) v3.1 uses three metric groups to calculate overall scores:Base,Temporal, andEnvironmental.

Base (E):Mandatory metrics assessing exploitability (e.g., attack vector) and impact (confidentiality, integrity, availability).

Temporal (A):Optional metrics reflecting the current state of the vulnerability (e.g., exploit availability, remediation level).

Environmental (F):Optional metrics tailoring the score to the organization’s context (e.g., security requirements).

B, C, D (Availability, Integrity, Confidentiality):These are subcomponents of the Base Impact metrics, not standalone groups.

G (Impact):A categorywithin Base, not a group.

H (Attack vector):A single Base metric, not a group.

Advancements in quantum computing pose a significant threat to current encryption systems, especially those based on the difficulty of factoring large prime numbers, such as RSA. Quantum computers have the potential to solve these problems exponentially faster than classical computers, making current cryptographic systems vulnerable.

Why Large Prime Numbers are Vulnerable:

Shor's Algorithm: Quantum computers can use Shor's algorithm to factorize large integers efficiently, which undermines the security of RSA encryption.

Cryptographic Breakthrough: The ability to quickly factor large prime numbers means that encrypted data, which relies on the hardness of thismathematical problem, can be decrypted.

Other options, while relevant, do not capture the primary reason for the shift towards new encryption algorithms:

B. Zero Trust security architectures: While important, the shift to homomorphic encryption is not the main driver for new encryption algorithms.

C. Perfect forward secrecy: It enhances security but is not the main reason for new encryption algorithms.

D. Real-time IP traffic capture: Quantum computers pose a more significant threat to the underlying cryptographic algorithms than to the real-time capture of traffic.

Step-by-Step Explanation:

Regression testing ensures that new changes do not break existing functionality. It would have identified the memory leak before deployment, preventing downtime.

Anacceptable use policy (AUP)defines what is considered appropriate use of corporate email and prevents unnecessary emails to personal accounts. This helps in reducing false DLP alerts while maintaining compliance.

Quarantining emails (A)is unnecessary since the content was not flagged as sensitive.

Encryption (C)secures emails but does not address overuse.

Phishing awareness training (D)is unrelated to policy enforcement for outgoing emails.

The most likely reason the device must be replaced is that the motherboard was not configured with a TPM (Trusted Platform Module) from the OEM (Original Equipment Manufacturer) supplier.

Why TPM is Necessary for Full Disk Encryption:

Hardware-Based Security: TPM provides a hardware-based mechanism to store encryption keys securely, which is essential for full disk encryption.

Compatibility: Full disk encryption solutions, such as BitLocker, require TPM to ensure that the encryption keys are securely stored and managed.

Integrity Checks: TPM enables system integrity checks during boot, ensuring that the device has not been tampered with.

Other options do not directly address the requirement for TPM in supporting full disk encryption:

A. The HSM is outdated: While HSM (Hardware Security Module) is important for security, it is not typically used for full disk encryption.

B. The vTPM was not properly initialized: vTPM (virtual TPM) is less common and not typically a reason for requiring hardware replacement.

C. The HSM is vulnerable to common exploits: This would require a firmware upgrade, not replacement of the device.

E. The HSM does not support sealing storage: Sealing storage is relevant but not the primary reason for requiring TPM for full disk encryption.

The ATT&CK (Adversarial Tactics, Techniques, and Common Knowledge) framework is the best tool for a security analyst to use for threat modeling when looking for gaps in detection capabilities based on Advanced Persistent Threats (APTs) that may target the industry. Here’s why:

Comprehensive Framework: ATT&CK provides a detailed and structured repository of known adversary tactics and techniques based on real-world observations. It helps organizations understand how attackers operate and what techniques they might use.

Gap Analysis: By mapping existing security controls against the ATT&CK matrix, analysts can identify which tactics and techniques are not adequately covered by current detection and mitigation measures.

Industry Relevance: The ATT&CK framework is continuously updated with the latest threat intelligence, making it highly relevant for industries facing APT threats. It provides insights into specific APT groups and their preferred methods of attack.

Disabling unneeded servicesreduces the attack surface by closing open ports.Patchingensures that endpoint protection software and operating systems are up-to-date, reducing vulnerability exposure.Removing unused accountseliminates access paths for malicious users exploiting dormant accounts. Secure boot, BIOS passwords, and drive encryption are important, but they address different layers of security than the vulnerabilities listed.

Step by Step Explanation:

Understanding the Scenario: Theorganization is using customer-managed encryption keys in the cloud, which is more expensive than using the cloud provider's free managed keys. The CISO needs to find a way to reduce costs without significantly weakening the security posture.

Analyzing the Answer Choices:

A. Utilize an on-premises HSM to locally manage keys: While on-premises HSMs offer strong security, they introduce additional costs and complexity (procurement, maintenance, etc.). This option is unlikely to reduce costs compared to cloud-based key management.

B. Adjust the configuration for cloud provider keys on data that is classified as public: This is the most practical and cost-effective approach. Data classified as public doesn't require the same level of protection as sensitive data. Using the cloud provider's free managed keys for public data can significantly reduce costs without compromising security, as the data is intended to be publicly accessible anyway.

Comprehensive and Detailed Explanation:

Best practice in CAS-005 network security design is to deploy:

NIDS passively via a port mirror (SPAN port) to avoid introducing latency or failure points.

NIPS inline in a strategic point, such as integrated with the main firewall, to actively block threats.This combination provides both visibility and active protection without overloading network paths.

The “cipher unavailable” message indicates that the client and server could not agree on a common cipher suite. After the OpenSSL update, the server likely dropped support for older, insecure ciphers (such as RC4 or 3DES) that legacy clients still use. The safest remediation is to update or configure the client applications to support modern, secure ciphers such as AES in Galois/Counter Mode (AES-GCM) or an equivalent strong cipher suite that is supported by the updated OpenSSL server.

Option A (SSL 3.0) is unsafe because SSL 3.0 is deprecated and vulnerable to multiple attacks (e.g., POODLE).

Option C (ECB mode) is insecure due to pattern leakage and should never be enforced.

Option D (ECC signatures) relates to key exchange and signatures, not to the “cipher unavailable” issue directly.

This approach aligns with SecurityX CAS-005 cryptographic interoperability guidance—modernize clients rather than reintroduce insecure protocols.

Code-signing within theCI/CD pipelineensures that only verified and signed code is deployed, mitigating the risk of supply chain attacks. Updating Python withaptitudeand updating modules withpipensures vulnerabilities are patched. Deploying the solution to production after testing maintains application availability while securing the development lifecycle.

Branch protection (B)applies only to version-controlled environments, which is not the case here.

NFS network share (C)does not address the deprecated Python vulnerability.

Version designation (D)does not eliminate security risks from outdated dependencies.

The most likely explanation for the issues encountered with the captive portal is that the TLS ciphers supported by the captive portal are deprecated. Here’s why:

TLS Cipher Suites: Modern browsers are continuously updated to support the latest security standards and often drop support for deprecated and insecure cipher suites. If the captive portal uses outdated TLS ciphers, newer browsers may refuse to connect, causing security errors.

HSTS and Browser Security: Browsers with HTTP Strict Transport Security (HSTS) enabled will not allow connections to sites with weak security configurations. Deprecated TLS ciphers would cause these browsers to block the connection.

Whencreating a threat model to identify vulnerabilities in an organization's infrastructure, prioritizing external-facing infrastructure with known exploited vulnerabilities is critical. Here’s why:

Exposure to Attack: External-facinginfrastructure is directly exposed to the internet, making it a primary target for attackers. Any vulnerabilities in this layer pose an immediate risk to the organization's security.

Known Exploited Vulnerabilities: Vulnerabilities that are already known and exploited in the wild are of higher concern because they are actively being used by attackers. Addressing these vulnerabilities reduces the risk of exploitation significantly.

Risk Mitigation: By prioritizing external-facing infrastructure with known exploited vulnerabilities, the organization can mitigate the most immediate and impactful threats, thereby improving overall security posture.

Collecting a large pool of behavioral observations requires handling vast datasets, which is the domain ofBig Data. Big Data technologies enable the storage, processing, and analysis of large-scale data (e.g., user behavior logs) to inform decisions, a key capability in security analytics.

Option A:Linear regression is a statistical method for modeling relationships, not collecting data.

Option B:Distributed consensus relates to agreement in distributed systems (e.g., blockchain), not data collection.

Option C:Big Data directly supports collecting and analyzing large datasets for insights, fitting the question perfectly.

Option D:Machine learning uses data to train models but relies on data being collected first, often via Big Data.

Removing unnecessary services from existing endpoints reduces the attack surface by minimizing the number of potential vulnerabilities attackers could exploit. This is a cost-effective method to harden devices without requiring new purchases, aligning perfectly with a purchasing freeze. Deploying new EDR solutions or disposing of devices would likely conflict with the resource freeze, and reimaging systems does not address minimizing services proactively.

Tokenizationreplaces sensitive data (e.g., PII) with non-sensitive placeholders while maintaining format consistency, ensuring compliancewithout disrupting testing. This method is commonly used forPCI-DSS and GDPR compliancewhile preserving data structure for functional tests.

Encryption (A)secures data but does not remove sensitivity or solve testing concerns.

Truncation (B)removes portions of data but may impact testing if format requirements are strict.

Synthetic data (C)can be useful but may not always match real-world scenarios perfectly for testing purposes.

The best location to test a newly released feature for an internal application, without affecting the production environment, is the staging environment. Here’s a detailed explanation:

Staging Environment: This environment closely mirrors the production environment in terms of hardware, software, configurations, and settings. It serves as a final testing ground before deploying changes to production. Testing in the staging environment ensures that the new feature will behave as expected in the actual production setup.

Isolation fromProduction: The staging environment is isolated from production, which means any issues arising from the new feature will not impact the live users or the integrity of the production data. This aligns with best practices in change management and risk mitigation.

Realistic Testing: Since the staging environment replicates the production environment, it provides realistic testing conditions. This helps in identifying potential issues that might not be apparent in a development or testing environment, which often have different configurations and workloads.

The strings utility extracts human-readable text from binary files. Security analysts use it to identify Indicators of Compromise (IoCs) such as URLs, IP addresses, filenames, and commands embedded in the malware.

Option A (reconstructing timeline) would require event logs or forensic timeline tools.

Option C (replicating the attack) involves execution in a sandbox, not static string extraction.

The table shows detailed information about products, includinglocation, chassis manufacturer, OS, application developer, and vendor. This type of information is typically assessed in a supply chain assessment to evaluate the security and reliability of components and services from different suppliers.

Why Supply Chain Assessment?

Component Evaluation: Assessing the origin and security of each component used in the products, including hardware, software, and third-party services.

Vendor Reliability: Evaluating the security practices and reliability of vendors involved in providing components or services.

Risk Management: Identifying potential risks associated with the supply chain, such as vulnerabilities in third-party components or insecure development practices.

Other types of assessments do not align with the detailed supplier and component information provided:

A. System: Focuses on individual system security, not the broader supply chain.

C. Quantitative: Focuses on numerical risk assessments, not supplier information.

D. Organizational: Focuses on internal organizational practices, not external suppliers.

Encrypting patient data at rest ensures that sensitive information is protected from unauthorized access, thereby maintaining patient privacy. Additionally, encryption supports data portability by allowing secure transfer and storage of data across different systems and devices without compromising confidentiality. This practice is crucial for healthcare providers to comply with regulations such as the Health Insurance Portability and Accountability Act (HIPAA), which mandates the protection of patient information.​

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The beststrategy for securely managing cryptographic material is to use a Hardware Security Module (HSM). Here’s why:

Security and Integrity: HSMs are specialized hardware devices designed to protect and manage digital keys. They provide high levels of physical and logical security, ensuring that cryptographic material is well protected against tampering and unauthorized access.

Centralized Key Management: Using HSMs allows for centralized management of cryptographic keys, reducing the risks associated with decentralized and potentially insecure key storage practices, such as on personal laptops.

Compliance and Best Practices: HSMs comply with various industry standards and regulations (such as FIPS 140-2) for secure key management. This ensures that the organization adheres to best practices and meets compliance requirements.

Homomorphic encryption allows computations to be performed on encrypted data without decrypting it, preserving confidentiality. However, its adoption faces significant challenges due to performance overhead. According to the CompTIA SecurityX CAS-005 study materials (Domain 3: Cybersecurity Technology, 3.3), homomorphic encryption requires substantial computational resources, which standard processors struggle to provide efficiently. Specialized hardware, such as coprocessors (e.g., GPUs or TPUs), is oftenneeded to handle the complex mathematical operations involved. The lack of widespread, optimized coprocessor support in existing infrastructure is a primary barrier to adoption.

Option A (Incomplete mathematical primitives):While early homomorphic encryption schemes had limitations, modern schemes (e.g., CKKS, BFV) have mature mathematical foundations, making this less of a challenge today.

Option B (No use cases):Use cases exist, such as secure cloud computing and privacy-preserving data analytics, so this is not accurate.

Option C (Quantum computers):Homomorphic encryption is not dependent on quantum computing, and quantum computers are unrelated to its current challenges.

Option D (Insufficient coprocessor support):This is the most accurate, as performance bottlenecks require specialized hardware that is not yet widely available or integrated.

Creatingsecure baseline imagesensuresconsistent, repeatabledeployment aligned with hardening standards. These images can be used acrosson-premises and cloud environments, ensuring compliance and reducing misconfigurations.

Vulnerability alerts (A)are reactive, not preventive.

Building images from scratch (C)is time-consuming and unnecessary if baselines exist.

Scripts for cleanup (D)are useful but do not prevent initial insecure configurations.

Privileged Access Management (PAM)restricts elevated permissions, reducing the risk of widespread ransomware attacks.Multi-Factor Authentication (MFA)protects against credential theft and ensures that even if passwords are compromised, accounts are not easily accessible.Network segmentationbreaks the flat network into secure zones, limiting lateral movement by attackers. SD-WAN and BGP relate to network routing and efficiency, not security architecture specifically. Remote access VPN secures external access but does not solve internal flat network issues. Network Access Control (NAC) is helpful but secondary compared to PAM, MFA, and segmentation in this context.

Programmable Logic Controllers (PLCs) in Operational Technology (OT) environments commonly useLadder Logic, a graphical programming language resembling electrical relay logic diagrams. It’s the most relevant for PLCs due to its widespread use in industrial automation.

Option A:Ladder Logic is the standard for PLC programming, making it the best choice.

Option B:Rust is modern and secure but not typically used for PLCs.

Option C:C is used in some embedded systems but less common for PLCs.

Option D:Python is versatile but not native to PLC programming.

Option E:Java is rare in PLC contexts.

When a security analyst receives a notification about an attack that appears to originate from an internal vulnerability scanner, it suggests that the scanner itself might have been compromised. This situation is critical because a compromised scanner can potentially conduct unauthorized scans, leak sensitive information, or execute malicious actions within the network. The appropriate first action involves containing the threat to prevent further damage and allow for a thorough investigation.

Here’s why quarantining the scanner sensor is the best immediate action:

Containment and Isolation: Quarantining the scanner will immediately prevent it from continuing any malicious activity or scans. This containment is crucial to protect the rest of the network from potential harm.

Forensic Analysis: By isolating the scanner, a forensic analysis can be performed to understand how it was compromised, what actions it took, and what data or systems might have been affected. This analysis will provide valuable insights into the nature of the attack and help in taking appropriate remedial actions.

Preventing Further Attacks: If the scanner is allowed to continue operating, it might execute more unauthorized actions, leading to greater damage. Quarantine ensures that the threat is neutralized promptly.

Root Cause Identification: A forensic analysis can help identify vulnerabilities in the scanner’s configuration, software, or underlying system that allowed the compromise. This information is essential for preventing future incidents.

Other options, while potentially useful in the long term, are not appropriate as immediate actions in this scenario:

A. Create an allow list for the vulnerability scanner IPs to avoid false positives: This action addresses false positives but does not mitigate the immediate threat posed by the compromised scanner.

B. Configure the scan policy to avoid targeting an out-of-scope host: This step is preventive for future scans but does not deal with the current incident where the scanner is already compromised.

C. Set network behavior analysis rules: While useful for ongoing monitoring and detection, this does not address the immediate need to stop the compromised scanner’s activities.

In conclusion, the first and most crucial action is to quarantine the scanner sensor to halt any malicious activity and perform a forensic analysis to understand the scope and nature of the compromise. This step ensures that the threat is contained and provides a basis for further remediation efforts.

The attacker gained domain control by collecting the KRBTGT hash (used for Kerberos tickets). Let’s evaluate:

A. Deleting SQLSV:Irrelevant since pass-the-hash failed there.

B. Reimaging ADMIN01S:Addresses the compromised host but not domain control.

C. Rotating KRBTGT password:Invalidates stolen Kerberos tickets, mitigating domain control per CAS-005’s focus on identity security.

Encrypting patient data at rest is a critical requirement for healthcare providers to ensure compliance with regulations such as the Health Insurance Portability and Accountability Act (HIPAA). The primary business requirement fulfilled by this practice is the protection of patient privacy while supporting the portability of medical information. By encrypting data at rest, healthcare providers safeguard sensitive patient information from unauthorized access, ensuring that privacy is maintained even if the storage media are compromised. Additionally, encryption supports the portability of patient records, allowing for secure transfer and access across different systems and locations while ensuring that privacy controls are in place.

The output indicates that the software tool contains hard-coded credentials, which attackers can exploit to bypass user access controls and load the database. The mostlikely recommendation is to remove hard-coded credentials from the source code. Here’s why:

Security Best Practices: Hard-coded credentials are a significant security risk because they can be easily discovered through reverse engineering or simple inspection of the code. Removing them reduces the risk of unauthorized access.

Credential Management: Credentials should be managed securely using environment variables, secure vaults, or configuration management tools that provide encryption and access controls.

Mitigation of Exploits: By eliminating hard-coded credentials, the organization can prevent attackers from easily bypassing authentication mechanisms and gaining unauthorized access to sensitive systems.

The security engineer should modify the following to fix the email migration issues:

Email CNAME Record: The email CNAME record must be changed to a type A record pointing to 192.168.1.10. This is because CNAME records should not be used where an IP address (A record) is required. Changing it to an A record ensures direct pointing to the correct IP.

TXT Record for DMARC: The TXT record must be changed to "v=dmarc ip4:192.168.1.10 include

com -all". This ensures proper configuration of DMARC (Domain-based Message Authentication, Reporting & Conformance) to include the correct IP address and the email service provider domain.

DMARC: Ensuring the DMARC record is correctly set up helps in preventing email spoofing and phishing, aligning with email security best practices.

Step by Step Explanation:

Understanding the Scenario: The question focuses on the historical design assumptions behind older operational technology (OT)systems, particularly in the context of command, control, and telemetry.

Analyzing the Answer Choices:

A. operating in an isolated/disconnected system: This is the most accurate assumption for many legacy OT systems. Historically, these systems weredesigned to operate in air-gapped environments, completely isolated from external networks (including the internet).

The issue is tracing the original source of requests in a tiered architecture with a load balancer. The web server logs show internal IPs (192.168.1.10), not the external client IPs, because the load balancer forwards requests without preserving the source. Enabling theX-Forwarded-Forheader on the load balancer adds the client’s original IP to the HTTP request headers, allowing downstream servers to log it. This ensures traceability without altering the architecture significantly.

Option A:Correct—X-Forwarded-For is the standard solution for preserving client IPs through load balancers.

Option B:A Host-based Intrusion Detection System (HIDS) detects anomalies but doesn’t address IP traceability.

Option C:A trusted CA certificate fixes the self-signed warning but is unrelated to source tracking.

Option D:Stored procedures improve database security but don’t help with IP logging.

Option E:Storing $_SERVER['REMOTE_ADDR'] captures the loadbalancer’s IP, not the client’s, unless X-Forwarded-For is enabled.

Segmentationis the best option to ensure the security of legacy badge readers that cannot be upgraded. Segmentation isolates the legacy devices on a separate network segment to minimize their exposure to potential threats. This approach reduces the attack surface by preventing unauthorized access from other parts of the network while still allowing necessary connectivity to the enterprise resource planning (ERP) system.

Vulnerability scans (B)are useful for identifying weaknesses but do not actively protect the badge readers.

Anti-malware (C)is ineffective since the badge readers use a legacy platform that likely does not support modern endpoint protection solutions.

The situation where several employees were contacted by the same individual impersonating a recruiter best describes aspear-phishing campaign. Here’s why:

Targeted Approach: Spear-phishing involves targeting specific individuals within an organization with personalized and convincing messages to trick them into divulging sensitive information or performing actions that compromise security.

Impersonation: The use of impersonation, in this case, a recruiter, is a common tactic in spear-phishing to gain the trust of the targeted individuals and increase the likelihood of a successful attack.

Correlated Contacts: The fact that several employees were contacted by the same individual suggests a coordinated effort to breach the organization’s security by targeting multiple points of entry through social engineering.

Comprehensive and Detailed Explanation:

Always-on VPN ensures that devices connect automatically to the corporate network whenever they are online, allowing seamless access to internal resources and enabling authentication against on-premises directory services (such as Active Directory). This supports centralized identity management, GPO enforcement, and compliance requirements.

Options B, C, and D involve local or peripheral resources, which are unaffected by VPN state.

The most appropriate technique to improve the cryptographic strength of a password-storage component in a web application without completely replacing the crypto-module is key stretching. Here's why:

Enhanced Security: Key stretching algorithms, such as PBKDF2, bcrypt, and scrypt, increase the computational effort required to derive the encryption key from the password, making brute-force attacks more difficult and time-consuming.

Compatibility: Key stretching can be implemented alongside existing cryptographic modules, enhancing their security without the need for a complete overhaul.

Industry Best Practices: Key stretching is a widely recommended practice for securely storing passwords, as it significantly improves resistance to password-cracking attacks.