CAS-005 CompTIA SecurityX Certification Exam Questions and Answers

Authenticated scans allow the scanner to verify installed patches and configurations, reducing false positives.

Other options:

A (CMDB updates) improve asset tracking but do not validate patch installations.

C (Advanced fingerprinting) improves accuracy but does not replace authentication.

D (Coordination with teams) is good practice but does not prevent false positives.

The best solution is Conditional Access (D). Conditional access policies enforce access requirements based on contextual signals such as device compliance, user identity, location, or risk profile. In this case, the administrator can configure conditional access to ensure that only managed, corporate-approved devices are allowed to access confidential data. If an employee attempts to use a personal laptop, the access request will be blocked or redirected to a secure process (e.g., virtual desktop).

Option A (OCSP stapling) relates to certificate revocation checking and does not control device access. Option B (CASB) provides cloud access visibility and control but is broader and less precise than enforcing direct device-level conditional policies. Option C (SOAR) orchestrates responses but is not primarily designed for access enforcement. Option E (package monitoring) detects software changes but does not prevent unauthorized device usage.

Conditional access is a core principle in Zero Trust and modern IAM, making it the best solution for ensuring that sensitive data can only be accessed from trusted devices.

When the cost to mitigate certain risks is higher than the asset values, the best approach is to purchase insurance. Thismethod allows the company to transfer the risk to an insurance provider, ensuring that financial losses are covered in the event of an incident. This approach is cost-effective and ensures that risks are prioritized appropriately without overspending on mitigation efforts.

Configuring a span port on the perimeter firewall to ingest logs is the best architectural change to ensure that all client proxy traffic is captured for analysis. Here’s why:

Comprehensive Traffic Capture: A span port (or mirror port) on the perimeter firewall can capture all inbound and outbound traffic, including traffic that might bypass the proxy. This ensures that all network traffic is available for analysis.

Centralized Logging: By capturing logs at the perimeter firewall, the organization can centralize logging and analysis, making it easier to detect and investigate anomalies.

Minimal Disruption: Implementing a span port is a non-intrusive method that does not require significant changes to the network architecture, thus minimizing disruption to existing services.

This scenario describes an attack where the attacker mimics the CEO’s voice to deceive the CFO, likely using AI-generated audio. According to the CompTIA SecurityX CAS-005 study guide (Domain 1: Security Strategy and Risk Management, 1.2), a deepfake attack involves using artificial intelligence to create realistic but fake audio, video, or other media to impersonate someone. In this case, the voice similarity suggests a deepfake audio attack, which is a targeted social engineering tactic.

Option A:Smishing involves SMS-based phishing, not voicecalls.

Option C:Automated exploit generation refers to creating software exploits, not impersonation.

Option D:Spear phishing targets specific individuals but typically via email, not voice-based impersonation.

Option B:Deepfake is the most accurate, as it describes AI-driven impersonation of the CEO’s voice.

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 most secure way to prevent inadvertent data disclosure when encrypted SSDs are reused is to securely delete the encryption keys used by the SSD. Without the encryption keys, the data on the SSD remains encrypted and is effectively unreadable, rendering any residual data useless. This method is more reliable and efficient than overwriting data multiple times or using other physical destruction methods.

The best way is to perform a Software Assurance Maturity Model (SAMM) assessment. SAMM provides a structured framework to evaluate current software security maturity across people, process, and technology. The assessment highlights gaps and generates a roadmap tailored to the organization’s development environment.

Option B (threat modeling) only applies to specific applications, not the entire SDLC process. Option C risks misalignment with technical practices by relying only on CISO goals. Option D (OWASP secure coding manual) is useful but provides guidelines, not a maturity-based roadmap.

CAS-005 stresses leveraging maturity models for structured, measurable improvements. SAMM directly addresses this by producing a customized, actionable roadmap for secure coding practices.

Animmutable databasepreventsmodifications or deletions, ensuring resilience against ransomware while maintaining multiple copies of data.

Implementing security and quality checks in a CI/CD pipeline ensures that:

Container images are scanned for vulnerabilities beforedeployment.

Version control is enforced, preventing unauthorized changes.

Hashes validate image integrity.

Other options:

A (Configuring ACLs on mesh networks) improves access control but does not ensure scanning.

C (Audits on container images) detect changes but do not enforce best practices.

D (Pulling from a vendor repository) does not ensure vulnerability scanning.

This scenario describes anenterprise VPN setup that requires machine authenticationbefore a user logs in. The best explanation for this requirement is that theVPN client selects the appropriate certificate automaticallybased on the key extension in the machine certificate.

Understanding the Key Extension Requirement:

PKI (Public Key Infrastructure)issues machine certificates that include specific key usages such asClient AuthenticationorIPSec IKE Intermediate.

Key usage extensionsdefine how a certificate can be used, ensuring that onlyvalid certificates are selected by the VPN client.

Why Option B is Correct:

The VPNautomaticallyselects the correct machine certificate with the appropriate key extension.

The process occurswithout user intervention, ensuring seamless VPN authentication before login.

Why Other Options Are Incorrect:

A (MFA requirement):Certificates used in this scenario are for machine authentication, not user MFA. MFA typically involves user credentials plus a second factor (like OTPs or biometrics), which isnot applicable here.

C (Wi-Fi connectivity before login):This refers topre-logon networking, which is a separate concept where devices authenticate to a Wi-Fi network before login, usually via 802.1X EAP-TLS. However, this question specifically mentions VPN authentication, not Wi-Fi authentication.

D (SSL VPN with certificates):While SSL VPNs do use certificates,this scenario involves machine certificates issued by an internal PKI, which are commonly used inIPSec VPNs, not SSL VPNs.

Vendor lock-in occurs when a client is overly dependent on a vendor, limiting flexibility. Risks include:

Option B:Vendors changing offerings (e.g., features, pricing) can disrupt the client, a key lock-in risk.

Option D:Decreased quality of service may result from reliance on a single vendor without alternatives.

Option A:Seamless data movement is a benefit, not a risk.

Option C:Sufficient service is neutral or positive, not a risk.

Option E:Multicloud is hindered by lock-in, not a risk of it.

Option F:Increased interoperability contradicts lock-in’s limitations.

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.

Based on the provided authentication logs, we observe that User1's accountexperienced multiple failed login attempts within a very short time span (at 8:01:23 AM on 12/15). This pattern indicates a potential brute-force attack or an attempt to gain unauthorized access. Here’s a breakdown of why disabling User1's account is the appropriate first step:

Failed Login Attempts: The logs show that User1 had four consecutive failed login attempts:

VM01 at 8:01:23 AM

VM08 at 8:01:23 AM

VM01 at 8:01:23 AM

VM08 at 8:01:23 AM

Security Protocols and Best Practices: According to CompTIA Security+ guidelines, multiple failed login attempts within a short timeframe should trigger an immediate response to prevent further potential unauthorized access attempts. This typically involves temporarily disabling the account to stop ongoing brute-force attacks.

Account Lockout Policy: Implementing an account lockout policy is a standard practice to thwart brute-force attacks. Disabling User1's account will align with these best practices and prevent further failed attempts, which might lead to successful unauthorized access if not addressed.

The logs show that the user connected fromToronto (104.18.16.29)andLos Angeles (95.67.137.12)within minutes. The sudden location change is a typical trigger forgeoblocking in a Next-Generation Firewall (NGFW), leading to theHR System being denied.

A compromised account (B)would show failed login attempts or unusual activities, but all other access attempts were allowed.

Business hours restriction (C)is unlikely since the user was granted access earlier.

Approved subnet issues (D)would affect all applications, not just HR System access.

Multicloud provider solutionsinvolve using services from more than one cloud provider to ensure resiliency and redundancy. In the event of a failure or SLA breach by one CSP, another provider can maintain service continuity. An on-premises backup could help, but does not address CSP-specific SLA concerns directly. Round-robin load balancing and active-active within the same tenant still depend on a single provider, thus posing risks if the CSP fails.

The best way to prevent application-focused attacks for a platform-as-a-service solution with a web-based front end is to create Web Application Firewall (WAF) policies for relevant programming languages. Here's why:

Application-Focused Attack Prevention: WAFs are designed to protect web applications by filtering and monitoring HTTP traffic between a web application and the Internet. They help prevent attacks such as SQL injection, cross-site scripting (XSS), and other application-layer attacks.

Customizable Rules: WAF policies can be tailored to the specific programming languages and frameworks used by the web application, providing targeted protection based on known vulnerabilities and attack patterns.

Real-Time Protection: WAFs provide real-time protection, blocking malicious requests before they reach the application, thereby enhancing the security posture of the platform.

Chain of custody ensures that evidence is protected, documented, and accounted for from the moment it is collected until it is presented in court or a legal proceeding. Properly maintaining chain of custody is critical to proving that the evidence has not been tampered with. Although encryption protects data during transit, and legal issues are important, without a documented chain of custody, the integrity of the evidence itself could be challenged and invalidated.

Proper parsing of data is crucial for the SIEM to accurately interpret and analyze the logs being forwarded by the log collector. If the data is not parsed correctly, the SIEM may misinterpret the logs, leading to false positives and inaccurate alerts. Ensuring that the log data is correctly parsed allows the SIEM to correlate and analyze the logs effectively, which is essential for accurate alerting and monitoring.

The best solution is to provide a hash of all data made available (D). Hashing ensures the integrity of the threat intelligence data provided to customers. Clients can verify that the data received via API matches the published hash, ensuring no tampering occurred in transit or at rest. This supports customer trust and aligns with the objective of protecting data integrity while maintaining availability.

Option A (API secret keys) improves authentication and reduces attack surface but does not address integrity or compute efficiency. Option B (publishing IoCs publicly) increases attack surface and reduces control over distribution, which conflicts with security objectives. Option C (rate limiting) helps availability and cost control but does not guarantee data integrity.

By providing hashes, the company ensures customers can validate authenticity regardless of delivery method, reducing the risk of manipulated IoCs. This approach also minimizes compute spend since hashing is lightweight compared to continuous verification processes.

Therefore, the strongest alignment with all stated objectives—availability, reduced spend, reduced attack surface, and integrity—is achieved by providing hashes of all threat intelligence data.

Attack surface reductionfocuses on minimizingunnecessary services, open ports, and vulnerabilities, reducing the exposure to potential adversaries. This aligns withzero trust and least privilege principles.

Secure Boot (A)helps ensure system integrity but does not minimize exposed services.

Disabling third-party integrations (C)may help, but broader attack surface reduction is the best first step.

Limiting access (D)is important but does not directly reduce exposed services.

Risk appetite is the amount of risk an organization is willing to accept to achieve its objectives. When operating with a constrained budget, understanding the organization's risk appetite is crucial because:

It helps prioritize security investments based on the level of risk the organization is willing to tolerate.

High-impact, low-likelihood events may be deemed acceptable if they fall within the organization's risk appetite, allowing for budget allocation to other critical areas.

Properly understanding and defining risk appetite ensures that limited resources are used effectively to manage risks that align with the organization's strategic goals.

The best option is Mandatory Access Control (MAC). In MAC, access decisions are centrally controlled by the system or administrators, not by individual users. This ensures that healthcare staff who enter patient information cannot grant access to others, thereby preventing accidental or malicious disclosure. MAC enforces strict policies based on data sensitivity and user clearance, which aligns with compliance requirements like HIPAA.

Option A (rule-based) defines access through specific rules but is not as rigidly enforced as MAC. Option B (attribute-based) is flexible but could still allow dynamic grants of access. Option D (discretionary) explicitly allows users to assign access rights, which is exactly what must be avoided in this scenario.

CAS-005 stresses using centralized, non-discretionary controls when protecting sensitive medical data, making MAC the correct choice for hospitals.

OWIN23 is running Windows 7, which is a legacy operating system. Many EDR solutions no longer provide full support for outdated operating systems like Windows 7, which has reached its end of life and is no longer receiving security updates from Microsoft. This makes such systems more vulnerable to infections and attacks, including remote access Trojans (RATs).

A. OWIN23 uses a legacy version of Windows that is not supported by the EDR: This is the most probable cause because the lack of support means that the EDR solution may not fully protect or monitor this system, making it an easy target for infections.

B. LN002 was not supported by the EDR solution and propagates the RAT: While LN002 is unmanaged, it is less likely to propagate the RAT to OWIN23 directly without an established vector.

C. The EDR has an unknown vulnerability that was exploited by the attacker: This is possible but less likely than the lack of support for an outdated OS.

D. OWIN29 spreads the malware through other hosts in the network: While this could happen, the status indicates OWIN29 is in a bypass mode, which might limit its interactions but does not directly explain the infection on OWIN23.

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.

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.

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.

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.

Determining if attacks are from the same actor requires unique attribution. Let’s analyze:

A. Code stylometry:Analyzes coding style to identify authorship, the best method for linking malware to a specific actor per CAS-005’s threat intelligence focus.

B. Common IOCs:Indicates similar attacks but not necessarily the same actor.

C. IOCextractions:Similar to B, lacks specificity for attribution.

The error message"NET::ERR_CERT_WEAK_SIGNATURE_ALGORITHM" indicates that the web browser is rejecting the certificate because it uses a weak signature algorithm. This commonly happens with self-signed certificates, which often use outdated or insecure algorithms.

Why Discontinue Self-Signed Certificates?

Security Compliance: Modern browsers enforce strict security standards and may reject certificates that do not comply with these standards.

Trusted Certificates: Using certificates from a trusted Certificate Authority (CA) ensures compliance with security standards and is less likely to be flagged as insecure.

Weak Signature Algorithm: Self-signed certificates might use weak algorithms like MD5 or SHA-1, which are considered insecure.

Other options do not address the specific cause of the certificate error:

A. Rewriting legacy web functions: Does not address the certificate issue.

B. Disabling deprecated ciphers: Useful for improving security but not related to the certificate error.

C. Blocking non-essential ports: This is unrelated to the issue of certificate validation.

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.

In a federated environment divided by region, if user identities are not synchronized across regions, authentication may be slow or fail when employees travel. CAS-005 IAM guidance states that identity synchronization ensures user attributes and credentials are consistently available in all regions, reducing latency and login issues.

Option A creates separate identities, which breaks single identity management.

Option C is unrelated to the login performance issue.

Option D may resolve SSO appliance sync but not cross-region identity data availability.

Microsegmentation is a critical strategy within Zero Trust architecture that enhances context-aware access systems by dividing the network into smaller, isolated segments. This reduces the attack surface and limits lateral movement of attackers within the network. It ensures that even if one segment is compromised, the attacker cannot easily access other segments. This granular approach to network security is essential for enforcing strict access controls and monitoring within Zero Trust environments.

OpenSSH vulnerabilityispublic facingand has acritical CVSS of 9.2.

Exploitable SSH services can lead to direct server compromise.

Although Apache has a higher score, it's internal.

FromCAS-005, Domain 3: Vulnerability Management:

“Prioritize external vulnerabilities with high CVSS and exposed attack surfaces.”

Reviewing the asset inventory allows the security team to identify all instances of the affected application versions within the organization. By knowing which systems are running the vulnerable versions, the team can assess the full scope of the impact, determine which systems might be compromised, and prioritize them for further investigation and remediation.

Performing a port scan (Option A) might help identify open ports but does not provide specific information about theapplication versions. Inspecting egress network traffic (Option B) and analyzing user behavior (Option D) are important steps in the incident response process but do not directly identify which versions of the application are affected.

The correct source is the Business Impact Analysis (BIA). A BIA provides context about which systems and applications are most critical to business operations, regulatory compliance, and customer obligations. While CVSS scores indicate severity in technical terms, they do not reflect the business impact of exploitation. For example, a medium-severity vulnerability on a critical payment system may pose more business risk than a high-severity vulnerability on a test server.

Option A (third-party risk review) focuses on vendor security posture, not internal remediation priorities. Option C (incident response playbook) guides response during active incidents, not vulnerability prioritization. Option D (crisis management plan) addresses executive-level communications during crises, not technical risk assessment.

By combining vulnerability scan data with BIA context, security teams can prioritize remediation efforts based on business-critical systems, ensuring the highest-risk vulnerabilities are remediated first. This aligns with CAS-005’s guidance on risk-based prioritization of remediation efforts.

Using X.509 certificates for authentication with HTTPS encrypts credentials in transit and provides server identity verification. In SecurityX CAS-005 objectives, securing internal web services with TLS and mutual authentication is a primary method to reduce credential interception or reuse.

802.1X EAP-TTLS is for network access control, not web authentication.

DNS security (DNSSEC) ensures DNS integrity, not web session encryption.

IDS rules help detect, but not prevent, credential exposure.

To design resilience in an enterprise system that can survive environmental catastrophes, recover within 24 hours, and be resilient to active exploitation, the best strategy is to allocate fully redundant and geographically distributed standby sites. Here’s why:

Geographical Redundancy: Having geographically distributed standby sites ensures that if one site is affected by an environmental catastrophe, the other sites can take over, providing continuity of operations.

Full Redundancy: Fully redundant sites mean that all critical systems and data are replicated, enabling quick recovery in the event of a critical loss of availability.

Resilience to Exploitation: Distributing resources across multiple sites reduces the risk of a single point of failure and increases resilience against targeted attacks.

The best solution is to implement an interactive honeypot (A). Honeypots are decoy systems designed to attract and observe adversary behavior in real time. When security tools cannot categorize suspicious inbound traffic, a honeypot provides an isolated environment where the suspicious activity can be redirected and monitored without risking production systems. By deploying an interactive honeypot, analysts can study attacker tactics, techniques, and procedures (TTPs), extract Indicators of Compromise (IoCs), and improve defensive controls.

Option B (mapping to known IoCs) fails because the activity cannot be categorized, implying it is novel or not yet identified in threat intelligence feeds. Option C (monitoring the dark web) provides intelligence about potential threats but does not address real-time inbound suspicious activity. Option D (UEBA) focuses on analyzing user and entity behaviors but is less effective for categorizing inbound external traffic.

By using honeypots, organizations gain visibility into new, unknown, or advanced attack techniques, which helps improve detection capabilities, enrich threat intelligence, and strengthen incident response.

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.

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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.

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.

When differentiating between valid and invalid findings from vulnerability scans, the systemsadministrator should verify that the scanning credentials are properly configured. Valid credentials ensure that the scanner can authenticate and access the systems being evaluated, providing accurate and comprehensive results. Without proper credentials, scans may miss vulnerabilities or generate false positives, making it difficult to prioritize and address the findings effectively.

In the context of improving incident response and reducing dwell time, the security analyst needs to focus on proactive measures that can quickly detect and alert on potential security breaches. Here’s a detailed analysis of the options provided:

A. Adjusting the SIEM to alert on attempts to visit phishing sites: While this is a useful measure to prevent phishing attacks, it primarily addresses external threats and doesn’t directly impact dwell time reduction, which focuses on the time a threat remains undetected within a network.

B. Allowing TRACE method traffic to enable better log correlation: The TRACE method in HTTP is used for debugging purposes, but enabling it can introduce security vulnerabilities. It’s not typically recommended for enhancing security monitoring or incident response.

C. Enabling alerting on all suspicious administrator behavior: This option directly targets the potential misuse of administrator accounts, which are often high-value targets for attackers. By monitoring and alerting on suspicious activities from admin accounts, the organization can quickly identify and respond to potential breaches, thereby reducing dwell time significantly. Suspicious behavior could include unusual login times, access to sensitive data not usually accessed by the admin, or any deviation from normal behavior patterns. This proactive monitoring is crucial for quick detection and response, aligning well with best practices in incident response.

D. Utilizing allow lists on the WAF for all users using GET methods: This measure is aimed at restricting access based on allowed lists, which can be effective in preventing unauthorized access but doesn’t specifically address the need for quick detection and response to internal threats.

The most likely cause of the anti-malware alerts on customer workstations is unsecure bundled libraries. When developing and deploying new applications, it is common for developers to use third-party libraries. If these libraries are not properly vetted for security, they can introduce vulnerabilities or malicious code.

Why Unsecure Bundled Libraries?

Third-Party Risks: Using libraries that are not secure can lead to malware infections if the libraries contain malicious code or vulnerabilities.

Code Dependencies: Libraries may have dependencies that are not secure, leading to potential security risks.

Common Issue: This is a frequent issue in software development where libraries are used for convenience but not properly vetted for security.

Other options, while relevant, are less likely to cause widespread anti-malware alerts:

A. Misconfigured code commit: Could lead to issues but less likely to trigger anti-malware alerts.

C. Invalid code signing certificate: Would lead to trust issues but not typically anti-malware alerts.

D. Data leakage: Relevant for privacy concerns but not directly related to anti-malware alerts.

The best approach for managing and monitoring IoT devices, such as thermostats, is to operate them on a separate network with no access to other internal devices. This segmentation ensures that the IoT devices are isolated from the main network, reducing the risk of potential security breaches affecting other critical systems. Additionally, this setup allows for secure vendor updates without exposing the broader network to potential vulnerabilities inherent in IoT devices.

The best action to address the requirement of accessing the historian server within a SCADA system is to isolate the historian server for connections only from the SCADAenvironment. Here’s why:

Security and Isolation: Isolating the historian server ensures that only authorized devices within the SCADA environment can connect to it. This minimizes the attack surface and protects sensitive data from unauthorized access.

Access Control: By restricting access to the historian server to only SCADA devices, the organization can better control and monitor interactions, ensuring that only legitimate queries and data retrievals occur.

Best Practices for Critical Infrastructure: Following the principle of least privilege, isolating critical components like the historian server is a standard practice in securing SCADA systems, reducing the risk of cyberattacks.

Incident response follows a standard process (e.g., NIST 800-61): Preparation, Identification, Containment, Eradication, Recovery, Lessons Learned. After identifying the attack (file and origin), the next step isContainment—limiting the spread or impact (e.g., isolating systems) before remediation or recovery.

Option A:Remediation (fixing the root cause) follows containment.

Option B:Correct—containment prevents further damage post-identification.

Option C:“Response” is too vague; it encompasses all steps.

Option D:Recovery (restoring systems) comes after containment and eradication.

Public Key Infrastructure (PKI) supports change management by securing messages (e.g., approvals, updates).Non-repudiation, provided via digital signatures, ensures a sender cannot deny sending a message, critical for auditability in change processes.

Option A:Correct—PKI’s digital signatures ensure non-repudiation.

Option B:Confidentiality (via encryption) is a PKI feature but less tied to change management’s focus on accountability.

Option C:Delivery receipts are not aPKI function; they’re protocol-specific (e.g., SMTP).

Option D:Attestation relates to verifying attributes, not a direct PKI message capability.

To protect company information on stolen mobile devices, implementingremote wipe proceduresensures data can be erased if a device is suspected lost or stolen.Biometric access controlwith enforced timeouts further secures the device, requiring biometric authentication periodically, thus limiting unauthorized access even if the device is stolen. Geofencing and certificates provide additional security layers but are less immediate protections against information exposure after theft. Application control and side-loading prevention are important for malware threats but less so for stolen device scenarios.

The sshd_config file is the main configuration file for the OpenSSH server. To disable weak CBC (Cipher Block Chaining) ciphers for SSH connections, the security engineer should modify the sshd_config file to update the list of allowed ciphers. This file typically contains settings for the SSH daemon, including which encryption algorithms are allowed.

By editing the /etc/ssh/sshd_config file and updating the Ciphers directive, weak ciphers can be removed, and only strong ciphers can be allowed. This change ensures that the SSH server does not use insecure encryption methods.

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.

Input sanitation is a critical process in cybersecurity that involvesvalidating and cleaning data provided by users to prevent malicious inputs from causing harm. In the context of AI concerns:

A. Model inversion involves an attacker inferring sensitive data from model outputs, typically requiring sophisticated methods beyond just manipulating input data.

B. Prompt Injection is a form of attack where an adversary provides malicious input to manipulate the behavior of AI models, particularly those dealing with natural language processing (NLP). Input sanitation directly addresses this by ensuring that inputs are cleaned and validated to remove potentially harmful commands or instructions that could alter the AI's behavior.

C. Data poisoning involves injecting malicious data into the training set to compromise the model. While input sanitation can help by filtering out bad data, data poisoning is typically addressed through robust data validation and monitoring during the model training phase, rather than real-time input sanitation.

D. Non-explainable model refers to the lack of transparency in how AI models make decisions. This concern is not addressed by input sanitation, as it relates more to model design and interpretability techniques.

Input sanitation is most relevant and effective for preventing Prompt Injection attacks, where the integrity of user inputs directly impacts the performance and security of AI models.

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.​

The best step is to query user behavior analytics (UBA) data. SIEM alerts provide potential security events, but without additional context, they may lead to false positives. UBA solutions detect anomalies by comparing user activity against baselines of normal behavior, highlighting unusual login patterns, lateral movement, or privilege escalation.

Option A (password manager logs) focuses only on credential use and lacks behavioral insight. Option B (dark web monitoring) helps identify compromised accounts but does not investigate the internal incident. Option C (audit logs for privileged actions) is useful but narrow in scope—it only covers administrator accounts.

By correlating SIEM data with UBA, the engineer can validate whether the flagged activity indicates real malicious behavior or benign anomalies. CAS-005 emphasizes advanced analytics integration (UEBA/UBA) to strengthen investigation and reduce false positives, making Option D the most effective choice.

To create a collection of use cases for detecting known threats and include them in a centralized library for use across multiple companies withdifferent vendors, Sigma rules are the best option. Here’s why:

Vendor-Agnostic Format: Sigma rules are a generic and open standard for writing SIEM (Security Information and Event Management) rules. They can be translated to specific query languages of different SIEM systems, making them highly versatile and applicable across various platforms.

Centralized Rule Management: By using Sigma rules, the cybersecurity architect can create a centralized library of detection rules that can be easily shared and implemented across different detection and monitoring systems used by the acquired companies. This ensures consistency in threat detection capabilities.

Ease of Use and Flexibility: Sigma provides a structured and straightforward format for defining detection logic. It allows for the easy creation, modification, and sharing of rules, facilitating collaboration and standardization across the organization.

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.

A Content Delivery Network (CDN) caches and distributes static and dynamic web content across multiple geographically distributed edge servers, reducing latency for global users. This directly addresses page-loading delays caused by distance from the primary data centers.

RASP is for runtime application security, not latency.

Remote journaling is for data replication, not performance optimization.

SASE can improve security and WAN routing, but a CDN is purpose-built for content delivery performance.

The logs reviewed for the user indicate that access is being denied due to time-based access restrictions. These restrictions are commonly implemented to limit access to systems during specific hours to enhance security. If a user attempts to authenticate outside of the allowed time window, access will be denied. This measure helps prevent unauthorized access during non-business hours, reducing the risk of security incidents.

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.

Phishing simulations are a proven method for reinforcing security awareness, meeting compliance training requirements, and improving user incident reporting. In CAS-005, social engineering testing is a recommended component of organizational security culture programs.

DoS attacks (A) and penetration tests (B) assess technical security, not user awareness.

Fake ransomware (D) can cause unnecessary alarm and operational disruption.

Device attestationensures that only corporate-approved devices can perform privileged actions in SaaS applications.Continuous authorizationmonitors ongoing device compliance, dynamically adjusting permissions based onsecurity posture.

Blocking connections (A)is too restrictive and does not accommodate BYOD.

Machine certificates (B)help with authentication but do not provide continuous security assessment.

MDM policies (D)secure mobile devices but do not apply real-time access controls for SaaS applications.

The correct regulation is COPPA (Children’s Online Privacy Protection Act). COPPA is a U.S. law that requires organizations to obtain parental consent and implement specific protections before collecting personal data from children under the age of 13. Since the legal counsel is advising about age-related sign-up requirements, the concern clearly points to COPPA compliance.

GDPR (A) is a European regulation governing privacy and data protection but is broader and not specifically tied to children’s age verification, though it has related provisions. LGPD (B) is Brazil’s data protection law, similar in scope to GDPR. PCI DSS (C) is focused on protecting cardholder data in payment environments, unrelated to age-related concerns.

CAS-005 covers the importance of aligning software platforms with legal and regulatory frameworks. For gaming and online services, COPPA compliance is crucial to avoid fines and reputational harm, ensuring the platform properly handles children’s data.

Understanding the Security Event:

HOST002 is the only device authorized for internet traffic. However, theSIEM logs show that VM002 is making network connections to web.corp.local.

This indicatesunauthorized access, which could bea sign of lateral movement or network infection.

This is ared flagfor potential malware, unauthorized software, or a compromised host.

Why Option D is Correct:

Unusual network traffic patternsare often an indicator of acompromised system.

VM002 should not be communicating externally, but it is.

This suggests a possiblebreach or malware infectionattempting to communicate with a command-and-control (C2) server.

Why Other Options Are Incorrect:

A (Misconfiguration):While a misconfiguration could explain the unauthorized connections, the pattern of activity suggests something more malicious.

B (Security incident on HOST002):The issue is not with HOST002. The suspicious activity isfrom VM002.

C (False positives):The repeated pattern of unauthorized connections makes false positivesunlikely.

To meet the requirements of having allendpoints establish telemetry with a SIEM, integrate into an XDR platform, and allow SOC services to monitor the XDR platform, the best approach is to implement Host Intrusion Prevention Systems (HIPS) and a host-based firewall. HIPS can provide detailed telemetry data to the SIEM and can be integrated into the XDR platform for comprehensive monitoring and response. The host-based firewall ensures that only authorized traffic is allowed, providing an additional layer of security.

CVE (Common Vulnerabilities and Exposures)provides unique identifiers for publicly known cybersecurity vulnerabilities and exposures. Each CVE entry includes a description and, often, remediation information. CVSS refers to scoring severity, CCE focuses on configuration issues, and CPE deals with naming standardized platforms and systems.

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.

For bulk PKI enrollment:

MDM integration with directory services streamlines certificate request and deployment per device, leveraging existing authentication methods.

Simple Certificate Enrollment Protocol (SCEP) with one-time passwords allows automated, secure, large-scale certificate issuance without manual CSR handling.

clientAuth templates are used for device authentication, but selecting it alone is insufficient without automated enrollment mechanisms.

A single certificate for all devices violates PKI security principles and compromises individual device accountability.

The Subject Alternative Name (SAN) field in an X.509 certificate specifies additional hostnames, FQDNs, or IP addresses that the certificate will secure. To allow mutual TLS authentication for multiple hostnames and an IP address, these identities must be included in the SAN field.

Organizational Unit (B) is an informational attribute, not related to TLS authentication.

Extended Key Usage (C) defines purpose (e.g., serverAuth, clientAuth) but not hostnames.

“Certificate extension” (D) is a generic term; SAN is the specific required extension.

SecurityX CAS-005 network architecture objectives emphasize limiting exposure of vulnerable systems by using application-aware firewalls with strict rule sets.

This approach directly reduces the attack surface by allowing only approved application traffic to and from the vulnerable systems, mitigating risk until systems are patched or replaced.

EDR (A) enhances detection but doesn’t inherently reduce the exposed services.

Network segmentation in monitor mode (B) doesn’t block threats.

IDS (C) detects activity but does not block it.

The most appropriate solution for the systems engineer to deploy is SELinux (Security-Enhanced Linux). Here's why:

Mandatory Access Control (MAC): SELinux enforces MAC policies, ensuring that only authorized users and processes can access specific resources. This helps in preventing unauthorized reading and modification of data and programs.

Access Vector Cache: SELinux utilizes an access vector cache (AVC) to improve performance. The AVC caches access decisions, reducing the need for repetitive policy lookups and thus improving system efficiency.

Security Mechanisms: SELinux provides a robust framework to enforce security policies and prevent bypassing of application security mechanisms. It controls access based on defined policies, ensuring that security measures are consistently applied.

Privilege Escalation and Process Interference: SELinux limits the ability of processes to escalate privileges and interfere with each other by enforcing strict access controls. This containment helps in isolating processes and minimizing the risk of privilege escalation attacks.

The actions described fall under Operational Security (OPSEC), which is the practice of identifying critical information, analyzing potential adversary intelligence collection, and implementing measures to protect sensitive details from disclosure. In this case, the ISAC report highlights how adversaries may use photos shared on social media as reconnaissance, revealing details about technology or configurations inside secure facilities.

By disabling cameras and location services on corporate devices and blocking access to social media from corporate and guest networks, the CISO is reducing the chance of inadvertent information disclosure. This prevents employees from unintentionally leaking images or metadata that adversaries could exploit.

Adversary emulation (A) involves simulating threat actors’ tactics in controlled exercises, which is not what is occurring here. Open-source intelligence (C) is the method adversaries use to gather data, not the defensive practice the CISO is implementing. Social engineering (D) describes manipulative attacks against humans, but this control is preventive, not reactive.

Thus, these measures are clear examples of Operational Security to limit information exposure.

The scenario describes a prolonged, stealthy operation where files were exfiltrated over three months via secure channels (TLS-protected HTTP) from unexpected systems, then ceased. This aligns with anAdvanced Persistent Threat (APT), characterized by long-term, targeted attacks aimed at data theft or surveillance, often using sophisticated methods to remain undetected.

Option A:Decrypting RSA with weak encryption implies a cryptographic attack, but TLS suggests modern encryption was used, and there’s no evidence of decryption here.

Option B:A zero-day attack exploits unknown vulnerabilities, but the duration and cessation suggest a planned operation, not a single exploit.

Option C:APT fits perfectly—slow, persistent exfiltration fromunusual systems indicates a coordinated, stealthy threat actor.

Option D:An on-path (man-in-the-middle) attack intercepts traffic, but there’s no indication of interception; the focus is on unauthorized transfers.

The most critical considerations are trust boundaries (C) and supply chain access (E). Trust boundaries define where sensitive data crosses between systems or organizations, requiring strict cryptographic protections—especially important in government and commercial environments subject to crypto-export controls.

Supply chain access is also critical because hardware and software are sourced from external vendors. If suppliers are compromised, attackers could introduce malicious code, backdoors, or tampered firmware, endangering customers worldwide.

Option A (contractual obligations) and B (legal hold) are compliance-related but not direct security threats. Option D (cloud services enumeration) is irrelevant unless the storage is cloud-based. Option F (homomorphic encryption) is an advanced technology but not required for base threat modeling.

CAS-005 highlights modeling adversary capabilities at trust boundaries and accounting for supply chain risks, making C and E the most important.

The first immediate action in an active incident iscontainment.Blocking the IP address (40.90.23.154)at the network edge prevents further communication with the malicious external server. Disabling PowerShell or removing local admin privileges are valid hardening steps, but containment by network control is the highest priority during an active compromise to stop data exfiltration or further command and control activity.

The requirements for archiving data and immutable backups directly align with legal hold compliance (E) and ransomware resilience (F).

Legal hold compliance ensures that organizations can retain data in a tamper-proof manner when required for litigation, regulatory mandates, or audits. Immutable backups satisfy this by preventing unauthorized changes or deletion, ensuring evidence and records are preserved.

Ransomware resilience is also a key factor. Immutable backups allow recovery from ransomware attacks, as attackers cannot encrypt or delete data stored in read-only or write-once media. This reduces downtime and supports business continuity.

Options A (crypto-export), B (supply chain), C (device attestation), and D (quality assurance) do not relate directly to data archiving or immutable storage.

CAS-005 stresses aligning security controls with business continuity and compliance requirements. By focusing on legal and ransomware-related considerations, the organization ensures both regulatory and operational resilience.