CompTIA CS0-003 Practice Test

Explanation:

In the Cyber Kill Chain, the Weaponization phase refers to the stage where a threat actor:

Develops or customizes malicious payloads (e.g., malware, exploit code)

Ensures the malware is packaged or modified to evade detection (such as endpoint security tools)

Prepares tools for delivery to the target

In this scenario, the attacker is:

Using OSINT (open-source intelligence) from forums to understand the victim’s defenses

Compiling and testing a malicious downloader to bypass endpoint protection

These are classic signs of Weaponization — creating a customized tool or payload ready to be delivered but not yet sent.

Why the other options are incorrect:

Reconnaissance:
→ This is the information-gathering stage, where the attacker identifies targets, collects public data, etc.

→ While OSINT is gathered, the key action here is tool creation and testing, not just informationcollection.

Delivery:
→ This is the phase where the attacker actually sends the payload to the victim (e.g., via phishing, drive-by download).

→ No delivery has occurred in the scenario.

Exploitation:
→ Happens when the payload is executed on the target system, taking advantage of a vulnerability.

→ This has not happened yet.

Reference:
CompTIA CySA+ CS0-003 Official Study Guide, section: Cyber Kill Chain (CKC).

Explanation:

Proper handling and reporting of evidence is crucial in incident response, particularly for legal and investigative purposes. If evidence (such as logs, system images, or communications) is not collected, preserved, and documented properly, it may become:

egally inadmissible in court

Questionable in integrity, leading to potential dismissal of a case

Useless in prosecution efforts

Maintaining a proper chain of custody, using forensically sound methods, and ensuring accurate documentation are all critical to making the evidence legally defensible.

This aligns with the Investigation and Reporting phase of incident response, especially when law enforcement or regulatory bodies are involved.

Why the other options are incorrect:

"To present a lessons-learned analysis..."
→ Lessons learned are important but do not require strict evidence handling.

"To ensure the evidence can be used in a postmortem analysis"
→ Postmortem uses data for internal review, but the legal chain of custody is not as critical here.

"To prevent the possible loss of a data source..."
→ This relates more to availability of data than to proper handling/reporting.

Reference:

CompTIA CySA+ CS0-003 Official Study Guide, section: Incident Response – Evidence Handling & Chain of Custody.

Explanation:

The question asks which vulnerability, identified in a recent scan with similar CVSSv3 scores but different base score metrics, a security analyst should remediate first based on the attack vector. The attack vector (AV) determines how easily a vulnerability can be exploited, with Network (AV:N) being the most critical due to its remote exploitability. The vulnerability with AV:N (option C) should be prioritized, as it poses the greatest risk in an internet-exposed environment, aligning with the CS0-003 exam’s Vulnerability Management (Domain 2) and Security Operations (Domain 1) objectives, which emphasize prioritizing remediation based on risk and exploitability.

Why C is Correct:

Attack Vector Priority:
The AV:N (Network) vector indicates the vulnerability can be exploited remotely over the internet or intranet, making it the most dangerous in an internet-exposed environment (common in prior healthcare-related questions, e.g., web servers). Remote exploitability increases the likelihood of attack compared to physical, adjacent, or local access.

Risk Assessment:
Exploitability: AV:N requires no physical or local presence, only low privileges (e.g., a compromised user account), making it highly exploitable by remote attackers.

Impact:
High CIA impacts (C:H/I:H/A:H) mean a successful exploit could lead to data breaches (e.g., PHI exposure), system compromise, or service disruption.

Context:
In a healthcare organization, a network-based vulnerability on a server (e.g., web or database server) risks HIPAA violations, making urgent remediation critical.

CS0-003 Alignment:
Domain 2 emphasizes prioritizing vulnerabilities based on exploitability (e.g., AV:N over AV:P) and impact, often tested via performance-based questions (PBQs). Domain 1 supports securing internet-facing systems, favoring remediation of network-based vulnerabilities.

Why Other Options Are Less Critical:

A. CVSS:3.0/AV:P/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H:
Reason: AV:P (Physical) requires the attacker to have physical access to the system (e.g., inserting a USB device), which is highly unlikely in a networked environment, especially for internet-facing servers. This significantly reduces exploitability compared to AV:N, making it the lowest priority.

B. CVSS:3.0/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H:
Reason: AV:A (Adjacent) requires the attacker to be on the same network (e.g., Wi-Fi, subnet), which is riskier than physical access but less exploitable than AV:N, as it requires proximity or prior network access. It’s less urgent than a remotely exploitable vulnerability.

D. CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H:
Reason: AV:L (Local) requires local access (e.g., a logged-in user or console access), which is less likely than network-based attacks for internet-facing systems. While risky (especially if credentials are compromised), it’s less immediate than AV:N, which allows attacks from anywhere.

Additional Context:

Prioritization Rationale:

Attack Vector Hierarchy: AV:N > AV:A > AV:L > AV:P, as network-based vulnerabilities are most accessible to attackers, especially for internet-exposed systems (e.g., web servers in healthcare).

CVSS Score: All options have high CIA impacts and low complexity/privileges, likely yielding similar scores (~8.3–8.7), so AV determines priority. AV:N typically scores higher (e.g., 8.7 vs. 8.3 for AV:L).

Example Vulnerability: Option C could represent a remote code execution flaw (e.g., in a web application) exploitable with minimal privileges, requiring urgent patching.

Healthcare Relevance: A network-based vulnerability risks PHI exposure or ransomware, critical for HIPAA compliance and patient data protection.

Remediation Steps: Patch the vulnerability, apply WAF rules, or implement microsegmentation (per prior questions) to limit exposure.

CS0-003 Relevance: Domain 2 tests CVSS-based prioritization, while Domain 1 emphasizes securing critical systems against remote threats.

Reference:

CompTIA CySA+ (CS0-003) Exam Objectives, Domains 1 (Security Operations) and 2 (Vulnerability Management), www.comptia.org, covering CVSS metrics and vulnerability prioritization.

Explanation:

The analyst has configured audit settings — this means they’ve enabled monitoring and logging of activities in the cloud environment. These settings do not prevent the incident from happening, nor do they correct it, but they do allow the organization to:

Detect unusual or unauthorized behavior

Track access and changes to cloud resources

Gather evidence for investigations and compliance

This fits the definition of a Detective control.

Why the other options are incorrect:

Preventive:
These controls aim to stop incidents before they occur (e.g., firewalls, access controls). Audit settings don’t block actions; they just log them.

Corrective:
These are applied after an incident to remediate or restore systems (e.g., patches, backups, system restores). Audit settings don’t fix anything.

Directive:
These are policies, procedures, or guidelines intended to guide user behavior (e.g., security awareness training, acceptable use policies). Audit settings are technical, not directive.

Reference:

CompTIA CySA+ CS0-003 Official Study Guide, section: Security Controls (Preventive, Detective, Corrective, Directive)

Explanation:

The question asks what the change management team failed to do, given that after updating the email client to the latest patch, only 15% of the workforce can use email, with Windows 11 users experiencing constant issues while Windows 10 users are unaffected. Testing is the most likely failure, as inadequate testing of the patch on Windows 11 systems before deployment would explain why the issue affects only Windows 11 users, indicating the patch was not properly vetted for compatibility. This aligns with the CS0-003 exam’s Security Operations (Domain 1) and Incident Response and Management (Domain 3) objectives, which emphasize the importance of change management processes, including testing, to prevent disruptions.

Why B is Correct:

Testing in Change Management:
Testing involves verifying that a change (e.g., a software patch) functions correctly across all affected systems before deployment. This includes compatibility testing in a staging environment that mirrors production (e.g., testing the email client patch on both Windows 10 and Windows 11 systems).

Failure Analysis:
The fact that Windows 11 users experience issues while Windows 10 users do not suggests the patch was not adequately tested on Windows 11, likely due to missing or incomplete testing in a representative environment. Proper testing would have identified compatibility issues, preventing widespread disruption.

Healthcare Context:
In a healthcare organization (per prior questions), email disruptions could hinder critical communications (e.g., patient care coordination), making thorough testing essential to ensure system reliability and HIPAA compliance.

CS0-003 Alignment:
Domain 1 emphasizes implementing robust change management to maintain operational stability, while Domain 3 supports preventing incidents through proper testing, both highlighting the need for pre-deployment validation.

Why Other Options Are Incorrect:

A. Implementation:
Reason: Implementation refers to deploying the change (e.g., applying the email client patch). The patch was successfully deployed, as it affects the workforce, so implementation was not the failure. The issue lies in the patch causing problems, pointing to a lack of testing.

C. Rollback:
Reason: Rollback involves reverting a change if it fails (e.g., restoring the previous email client version). While rollback may be needed now to resolve the issue, the question asks what was failed during the change process, and rollback occurs post-failure, not as a preventive step. Testing is the proactive failure here.

D. Validation:
Reason: Validation confirms that the change meets its intended purpose post-deployment (e.g., verifying email functionality after the patch). While validation may reveal the issue now, the root failure was not testing the patch on Windows 11 before deployment, as validation follows implementation. Testing is the more precise failure in this context.

Additional Context:

Change Management Process

Testing: Conduct unit, integration, and compatibility tests in a staging environment (e.g., test the patch on Windows 11 VMs).

Implementation: Deploy the patch to production.

Validation: Verify functionality post-deployment.

Rollback: Revert if issues are detected.

Scenario Details: The patch works for Windows 10 but fails for Windows 11, suggesting a compatibility issue specific to Windows 11 (e.g., API changes, driver conflicts). Testing in a Windows 11 environment would have caught this.

Healthcare Relevance: Email outages in healthcare could delay critical communications, impacting patient care or compliance. Testing ensures system reliability.

CS0-003 Relevance: Domain 1 tests change management processes, while Domain 3 emphasizes preventing disruptions through thorough preparation, often via performance-based questions (PBQs).

Reference:

CompTIA CySA+ (CS0-003) Exam Objectives, Domains 1 (Security Operations) and 3 (Incident Response and Management), www.comptia.org, covering change management and incident prevention.

Explanation:

This scenario involves potential insider threat behavior and legal implications (e.g., solicitation, non-compete violations, misuse of company data). However, Joe has not officially resigned, and no technical breach has been confirmed yet.

Taking unilateral technical actions like wiping or isolating his system without proper legal or HR review could:

Violate internal policy or employment laws

Interfere with a future legal case

Escalate the situation prematurely

The best practice in such cases is to escalate the issue to HR and legal counsel first, and only proceed with technical actions after proper authorization is given.

Why the other options are incorrect:

Isolate Joe’s PC from the network:

Premature without evidence of a data breach or approval from HR/legal.

Reimage the PC:

This would destroy potential evidence and could interfere with any internal or legal investigation.

Remote wipe using MDM:

Again, this action is destructive and might violate internal policy or legal process.

Reference:

CompTIA CySA+ CS0-003 Official Study Guide, topic: Insider Threats & Incident Response Process.

Explanation:

The question asks for the most likely reason to include lessons learned in an after-action report (AAR) following a significant security incident, as requested by the management team. Identifying areas of improvement in the incident response process is the primary purpose of including lessons learned, as it helps the organization analyze what went well, what didn’t, and how to enhance future responses to reduce risk and improve efficiency. This aligns with the CS0-003 exam’s Incident Response and Management (Domain 3) and Reporting and Communication (Domain 4) objectives, which emphasize post-incident analysis and process improvement.

Why C is Correct:

Purpose of Lessons Learned: Lessons learned in an AAR document successes, failures, and gaps in the incident response process (e.g., delays in containment, communication breakdowns). They provide actionable insights to refine procedures, tools, or training, ensuring better preparedness for future incidents.

Management’s Interest: The management team seeks lessons learned to understand how to strengthen the organization’s security posture, reduce downtime, and mitigate risks, particularly for critical incidents. This is a proactive step to enhance resilience.

Healthcare Context: In a healthcare organization (per prior questions), lessons learned help improve responses to incidents like ransomware or PHI breaches, ensuring HIPAA compliance and minimizing patient data risks by addressing process weaknesses.

CS0-003 Alignment: Domain 3 emphasizes post-incident analysis to improve response processes, while Domain 4 focuses on reporting actionable insights to management, both prioritizing lessons learned for improvement.

Why Other Options Are Incorrect:

A. To satisfy regulatory requirements for incident reporting
Reason: While regulatory requirements (e.g., HIPAA, GDPR) may mandate incident reporting, these typically focus on breach details (e.g., scope, impact, mitigation) rather than lessons learned. Lessons learned are internal process improvements, not a regulatory requirement, making this less likely.

B. To hold other departments accountable
Reason: Lessons learned aim to improve processes, not to assign blame. While an AAR may identify departmental failures (e.g., IT not patching systems), the primary goal is constructive improvement, not accountability, which could be addressed separately (e.g., via audits).

D. To highlight the notable practices of the organization’s incident response team
Reason: While an AAR may note successful practices, the primary focus of lessons learned is to identify gaps and areas for improvement, not to solely praise the team. Highlighting successes is secondary to enhancing future responses.

Additional Context:

Lessons Learned Process:

Review the incident timeline (e.g., detection, containment, eradication).

Identify gaps (e.g., slow EDR deployment, per prior questions, or misconfigured SIEM correlation).

Propose improvements (e.g., enhance NTP synchronization, per prior questions, or improve microsegmentation).

Example: “Delayed containment due to unsynchronized logs; implement NTP checks.”

AAR Structure: Includes incident summary, timeline, impact, response actions, and lessons learned, with recommendations for training, tools, or process changes.

Healthcare Relevance: Lessons learned ensure faster responses to future PHI breaches, reducing regulatory and operational risks.

CS0-003 Relevance: Domain 3 tests post-incident analysis, often via performance-based questions (PBQs), while Domain 4 emphasizes clear reporting to management.

Reference:

CompTIA CySA+ (CS0-003) Exam Objectives, Domains 3 (Incident Response and Management) and 4 (Reporting and Communication), covering post-incident analysis and AARs.

Explanation:

MITRE ATT&CK (Adversarial Tactics, Techniques, and Common Knowledge) is a globally accessible framework that provides detailed information about the:

Tactics: The "why" of an attack (e.g., privilege escalation, exfiltration)

Techniques: The "how" attackers achieve their goals (e.g., phishing, lateral movement)

Procedures: Real-world implementations used by threat actors

These collectively make up the TTPs (Tactics, Techniques, and Procedures) of cybercriminals. ATT&CK helps defenders understand, detect, and respond to threats based on actual observed behavior.

Why the other options are incorrect:

ZenMAP:
A graphical front-end for Nmap, used for network scanning, not for learning TTPs.

National Institute of Standards and Technology (NIST):
Provides cybersecurity standards and best practices, not a TTP-specific framework.

theHarvester:
An OSINT tool for gathering emails, domains, and IPs—used in reconnaissance, not for analyzing TTPs.

Reference:

CompTIA CySA+ CS0-003 Official Study Guide, Domain 1.3:

Explanation:

The question asks which solution a security analyst should deploy to ensure users only access web-based software that has been pre-approved by the organization. Allowlisting is the most effective approach, as it restricts access to only explicitly approved web-based applications or URLs, preventing users from accessing unapproved or potentially malicious software. This aligns with the CS0-003 exam’s Security Operations (Domain 1) and Vulnerability Management (Domain 2) objectives, which emphasize implementing controls to enforce security policies and reduce attack surfaces.

Why B is Correct:

Allowlisting Overview: Allowlisting (or whitelisting) permits access only to pre-approved resources (e.g., specific URLs, domains, or applications) while blocking all others. For web-based software, an allowlist can be enforced via web filters, proxies, or firewalls to restrict users to approved SaaS applications (e.g., Microsoft 365, Salesforce) or internal web tools.

Effectiveness: By defining a list of approved web-based software (e.g., https://approvedapp.com), allowlisting ensures users cannot access unapproved or malicious web applications, reducing risks like phishing, malware, or data leaks. It’s a proactive control tailored to the requirement of limiting access to pre-approved software.

Healthcare Context: In a healthcare organization (per prior questions), allowlisting ensures users only access approved systems (e.g., EHR portals), protecting PHI and ensuring HIPAA compliance by preventing unauthorized SaaS or malicious sites.

CS0-003 Alignment: Domain 1 emphasizes implementing access controls to enforce security policies, while Domain 2 supports reducing vulnerabilities by restricting unapproved software usage.

Why Other Options Are Incorrect:

A. Blocklisting
Reason: Blocklisting (or blacklisting) denies access to known malicious or unapproved resources (e.g., specific URLs or domains) but allows all others by default. This is less secure, as new or unknown malicious web-based software could bypass the blocklist, failing to ensure only pre-approved software is used.

C. Graylisting
Reason: Graylisting is typically used in email security to temporarily reject messages from unknown senders, requiring resending for verification. It’s irrelevant to controlling access to web-based software and doesn’t enforce an approved list.

D. Webhooks
Reason: Webhooks are mechanisms for sending real-time data between applications (e.g., triggering a notification when an event occurs). They are unrelated to access control or restricting users to approved web-based software, making this option irrelevant.

Additional Context:

Allowlisting Implementation:

Use a web proxy or firewall (e.g., Palo Alto, Zscaler) to enforce an allowlist of approved URLs or domains (e.g., *.office.com, *.salesforce.com).

Configure browser policies (e.g., via Group Policy on Windows) to restrict access to approved web applications.

Example: Allow https://ehr.company.com for a healthcare EHR system while blocking all other SaaS platforms.

Healthcare Relevance: Restricting users to approved web-based software prevents access to unvetted SaaS tools that could expose PHI or introduce vulnerabilities, aligning with HIPAA requirements.

CS0-003 Relevance: Domain 1 tests implementing application control policies, while Domain 2 emphasizes reducing risks from unapproved software, often via performance-based questions (PBQs).

Reference:

CompTIA CySA+ (CS0-003) Exam Objectives, Domains 1 (Security Operations) and 2 (Vulnerability Management), covering access controls and software restrictions.

Explanation:

The CVSS v3.1 Temporal Metric: Exploit Code Maturity reflects how widely available and functional exploit code is for a given vulnerability. When exploit code becomes publicly available, especially if it is easy to use, this increases the risk because attackers can act more easily and quickly. In this case, the critical vulnerability had publicly available exploit code for several days—this directly affects the "Exploit Code Maturity" by increasing it from something like:

Unproven or PoC (Proof of Concept)

➜ to

Functional or Wide availability

This metric directly lowers the temporal score, increasing the urgency for remediation.

Why other options are incorrect:

Remediation level:
Refers to the availability of patches or fixes, not exploit code.

Report confidence:
Deals with how confidently the vulnerability is known and confirmed, not its exploitability.

Availability (A):
This is a base metric, not a temporal metric, and refers to system availability impact, not exploit code exposure.

Reference:
CompTIA CySA+ CS0-003 Official Study Guide, Domain 1.1 – CVSS Metrics.