CAS-005 CompTIA SecurityX Certification Exam Free Practice Exam Questions (2025 Updated)

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.

The malware uses TCP 4444 to move laterally between systems. A host-based firewall can block unauthorized communication ports (like TCP 4444) on each workstation, preventing malware from establishing connections and spreading. Configuring the CPU's NX bit and enabling ASLR primarily help in mitigating memory-based exploits, not in stopping lateral movement. Enabling UEFI ensures boot integrity but does not mitigate active lateral communication. An edge firewall would protect the network perimeter, not internal workstation-to-workstation communication.

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.

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.

B. Pre-commit code linting: Linting tools analyze code for syntax errors andadherence to coding standards before the code is committed to the repository. This helps catch minor code issues early in the development process, reducing the likelihood of deployment failures.

D. Automated regression testing: Automated regression tests ensure that new code changes do not introduce bugs or regressions into the existing codebase. By running these tests automatically during the deployment process, developers can catch issues early and ensure the stability of the development environment.

Other options:

A. Software composition analysis: This helps identify vulnerabilities in third-party components but does not directly address code quality or deployment failures.

C. Repository branch protection: While this can help manage the code submission process, it does not directly prevent deployment failures caused by code issues or security check failures.

E. Code submit authorization workflow: This manages who can submit code but does not address the quality of the code being submitted.

F. Pipeline compliance scanning: This checks for compliance with security policies but does not address syntax or regression issues.

On-path decryption attacks, such as BEAST (Browser Exploit Against SSL/TLS) and other related vulnerabilities, often exploit weaknesses in the implementation of CBC (Cipher Block Chaining) mode. To mitigate these attacks, the following actions are recommended:

B. Removing support for CBC-based key exchange and signing algorithms: CBC mode is vulnerable to certain attacks like BEAST. By removing support for CBC-based ciphers, you can eliminate one of the primary vectors for these attacks. Instead, use modern cipher modes like GCM (Galois/Counter Mode) which offer better security properties.

C. Adding TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA256: This cipher suite uses Elliptic Curve Diffie-Hellman Ephemeral (ECDHE) for key exchange, which provides perfect forward secrecy. It also uses AES in GCM mode, which is not susceptible to the same attacks as CBC. SHA-256 is a strong hash function that ensures data integrity.

Comprehensive and Detailed Explanation:

Qualitative risk assessment is used when quantitative data (monetary loss, exact downtime cost, RTO) is unavailable or unreliable. The SecurityX CAS-005 GRC objectives note that qualitative methods rely on expert judgment, likelihood scales, and impact ratings rather than financial calculations. In this case, insufficient metrics rule out quantitative analysis.

Option A (work experience) is irrelevant to the choice of assessment type.

Option C (risk register) supports tracking, not selecting the assessment method.

Option D describes a quantitative goal, which is not possible with the given lack of metrics.

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 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.

Sinkholing, or DNS sinkholing, is a method used to redirect malicious traffic to a safe destination. This technique is often employed by security teams to prevent access to malicious domains by substituting a benign destination IP address.

In the given logs, users from the finance department are accessing www.bank.com and receiving HTTP status code 495. This status code is typically indicative of a client certificate error, which can occur if the DNS traffic is being manipulated or redirected incorrectly. The consistency in receiving the same HTTP status code across different users suggests a systematic issue rather than an isolated incident.

Recursive DNS resolution failure (A) would generally lead to inability to resolve DNS at all, not to a specific HTTP error.

DNS poisoning (B) could result in usersbeing directed to malicious sites, but again, would likely result in a different set of errors or unusual activity.

Incorrect DNS setup (D) would likely cause broader resolution issues rather than targeted errors like the one seen here.

By reviewing the provided data, it is evident that the DNS traffic for www.bank.com is being rerouted improperly, resulting in consistent HTTP 495 errors for the finance department users. Hence, the most likely cause is that the DNS traffic is being sinkholed.

Limiting the platform's abilities to only non-sensitive functions helps to mitigate risks associated with AI operations. By ensuring that the AI-enabled digital worker is only allowed to perform tasks that do not involve sensitive or critical data, the organization reduces the potential impact of any security breaches or misuse.

Enhancing the training model's effectiveness (Option B) is important but does not directly address security guardrails. Granting the system the ability to self-govern (Option C) could increase risk as it may act beyond the organization's control. Requiring end-user acknowledgement of organizational policies (Option D) is a good practice but does not implement technical guardrails to secure the AI environment.

Building playbooks for different scenarios and performing regular table-top exercises directly addresses the issues identified in the lessons-learned review. Here's why:

Lost important information for further analysis: Playbooks outline step-by-step procedures for incident response, ensuring that team members know exactly what to document and how to preserve evidence.

Did not utilize the chain of communication: Playbooks include communication protocols, specifying who to notify and when. Regular table-top exercises reinforce these communication channels, ensuring they are followed during actual incidents.

Did not follow the right steps for a proper response: Playbooks provide a clear sequence of actions to be taken during various types of incidents, helping the team to respond in a structured and effective manner. Regular exercises allow the team to practice these steps, identifying and correcting any deviations from the plan.

Investing in better forensic tools (Option A) or requiring certifications (Option C) are also valuable, but they do not directly address the procedural and communication gaps identified. Publishing and enforcing the incident response policy (Option D) is important but not as practical and hands-on as playbooks and exercises in ensuring the team is prepared.

To prevent unauthorized applications from running, the company needs a mechanism to explicitly define and enforce which applications are allowed to execute. "Permit listing" (often referred to as "whitelisting" in security contexts) is the most effective solution here. It involves creating a list of approved applications, and only those on the list are permitted to run, blocking all others by default. This directly addresses the root cause—users installing unapproved software—by restricting execution to only authorized programs.

Option A (Signing):Code signing ensures the authenticity and integrity of software by verifying it comes from a trusted source and hasn’t been tampered with. While useful, it doesn’t inherently prevent unauthorized applications from running unless combined with a policy like whitelisting.

Option B (Access control):Access control governs who can access systems or resources but doesn’t specifically restrict which applications can execute. It’s too broad for this scenario.

Option C (HIPS):A Host-based Intrusion Prevention System (HIPS) can detect and block malicious behavior, but it’s reactive and relies on signatures or heuristics, not a proactive allow-only approach.

Option D (Permit listing):This is the best fit, as it proactively enforces a policy where only explicitly authorized applications can run, preventing malware introduced by unauthorized software.

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.

Comprehensive and Detailed Explanation:

The code snippet exposes a hardcoded access token in a public repository. According to SecurityX CAS-005 secure coding best practices, the immediate action must be to revoke the exposed secret to prevent unauthorized access.

Removing the code from public view without revoking the token leaves the secret still usable by any attacker who has already seen or copied it.

SAST scanning would detect the issue but not mitigate it immediately.

Security awareness training is a long-term prevention measure but does not fix the immediate exposure.Revoking the secret first stops ongoing exploitation, after which the code can be removed, and preventative measures can be implemented.

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 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.

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.

Managing telemetry and differentiating it by office requires a way to categorize data. Let’s evaluate:

A. Sensor placement:Useful for data collection but doesn’t inherently differentiate by office.

B. Data labeling:Assigns metadata (e.g., office location) to telemetry, enabling differentiation. This aligns with CAS-005’s focus on data management for security operations.

C. Continuous monitoring:Ensures ongoing data collection but doesn’t address differentiation.