CompTIA CS0-003 Practice Test

Summary
The Payment Card Industry Data Security Standard (PCI DSS) is a contractual requirement enforced by the payment card brands (e.g., Visa, Mastercard, American Express) through the acquiring banks that process merchant transactions. In the event of a breach involving cardholder data, the immediate and primary responsibility of the breached organization is to notify its payment card partners, who will then manage the broader response, including alerting the card brands and potentially law enforcement.

Correct Option

D. Card issuer
Under PCI DSS compliance rules, a merchant that experiences a breach must immediately report the incident to their acquiring bank (the card issuer that processes their payments) and, if known, the relevant card brands (e.g., Visa, Mastercard).

The card issuer/acquirer is the entity that has the direct business relationship with the merchant and is contractually responsible for enforcing PCI DSS. They will act as the central point for the incident response, guiding the merchant on next steps, initiating forensic investigations, and managing communication with the payment card networks. Reporting to them fulfills the primary PCI DSS breach notification requirement.

Incorrect Options

A. PCI Security Standards Council
The PCI Security Standards Council (SSC) is the body that develops and manages the PCI DSS standards. It is not a regulatory or enforcement body and does not handle individual breach reports from organizations. Enforcement is managed by the payment card brands and acquiring banks.

B. Local law enforcement
While it is often prudent and sometimes legally required to report a significant data breach to local law enforcement, this is not the specific mandate of the PCI DSS standard. PCI DSS notification requirements are focused on the payment card ecosystem (acquirers and card brands), not government bodies.

C. Federal law enforcement
Similar to local law enforcement, involving federal agencies (like the FBI in the U.S.) may occur for major breaches, especially those involving cybercrime. However, this is not the direct reporting requirement stipulated by the PCI DSS contractual agreement. The primary obligation is to the card issuer/acquirer.

Reference
PCI Security Standards Council Official Website - Responding to a Compromise: The PCI SSC documentation outlines that in the event of a breach, an entity must "Alert appropriate parties (for example, acquirer, payment brand(s)) immediately." This confirms that the card issuer/acquirer is the primary point of contact, not the Council itself or law enforcement as a first step under the standard's terms.

Summary
The breach has exposed all employee credentials, making them available to attackers. While forcing immediate password changes (Option B) is a necessary first step, it only protects against reuse of the exact leaked passwords. Implementing multifactor authentication (MFA) provides a superior security control by requiring a second, independent form of verification beyond the password. This renders the stolen credentials useless on their own, significantly reducing the impact of the breach.

Correct Option

A. Multifactor authentication
MFA fundamentally changes the authentication process by requiring two or more pieces of evidence (factors) to grant access. Even if an attacker possesses the correct username and password (a "something you know" factor), they would be unable to provide the second factor (e.g., a code from an app, a biometric, "something you have"). This directly and most effectively reduces the impact of the credential leak by neutralizing the utility of the stolen passwords, preventing account takeover and lateral movement by the attackers using the compromised credentials.

Incorrect Options

B. Password changes
While forcing password changes is an immediate and essential reactive step, it is a weaker remediation on its own. It does not protect against the initial window of exposure between the leak and the change, and it offers no protection if the new password is weak or is subsequently phished or stolen again. MFA provides a more robust, proactive security layer.

C. System hardening
System hardening involves reducing the attack surface of systems by removing unnecessary services, applying patches, and tightening configurations. While a critical security practice, it does not directly address the specific problem of stolen user credentials being used for unauthorized access. It is a preventative control for vulnerabilities, not a remediation for compromised authentication secrets.

D. Password encryption
Passwords should already be hashed (a form of one-way encryption) when stored in a database. The fact that they were "leaked" means the attackers likely gained access to this hashed data. The remediation is not to change the storage encryption, but to change the authentication process itself (via MFA) to make the stolen data less valuable.

Reference
NIST Special Publication 800-63B - Digital Identity Guidelines: This standard strongly recommends the use of multi-factor authentication to protect against credential stuffing and the use of stolen passwords. It states that verifiers (services) "SHALL require multi-factor authentication" for certain scenarios and emphasizes that MFA is a critical control to mitigate the risk of compromised authenticators.

Summary
The core problem is an overwhelming volume of duplicate alerts, which wastes analyst time on manual triage and closure. A Security Orchestration, Automation, and Response (SOAR) platform is specifically designed to automate such repetitive, routine security tasks. It can be programmed with playbooks to automatically identify, correlate, and close duplicate alarms as they are ingested, significantly reducing the analyst's workload with minimal ongoing effort after initial setup.

Correct Option

A. SOAR
A SOAR platform excels at automating incident response workflows. A playbook can be created to group similar alerts based on common attributes (e.g., same source IP, destination IP, alert name, and timestamp).

Once duplicates are identified by the playbook's logic, the SOAR platform can automatically execute the action to close them, or group them into a single master incident. This automation directly addresses the "least effort" requirement by handling the task without manual analyst intervention.

Incorrect Options

B. API
An API (Application Programming Interface) is a method for different software applications to communicate. While a SOAR platform uses APIs to perform its automation, the API itself is just a tool or a protocol, not a solution. It does not, on its own, reduce alert volume.

C. XDR
Extended Detection and Response (XDR) is a platform that improves threat detection by integrating and correlating data from multiple security layers (endpoint, network, cloud). Its primary goal is better detection and visibility, not the automation of response tasks like closing duplicate tickets. While it might generate higher-fidelity alerts, it doesn't automatically resolve the duplicate alert problem.

D. REST
REST (Representational State Transfer) is an architectural style for designing networked applications, most commonly implemented via web APIs. Like a general API, it is an enabling technology for systems like SOAR to function, but it is not a security solution that can be "configured" to reduce alarm duplicates.

Reference
Gartner Definition of SOAR: Gartner, who coined the term, defines SOAR platforms as solutions that "allow organizations to define, prioritize and drive security incident response activities according to a standard workflow." This includes the automation of repetitive tasks, such as the deduplication and closure of common, low-fidelity alerts, which is a primary use case for the technology.

Summary
The vulnerability exists on port 3389, which is the default port for the Remote Desktop Protocol (RDP). A Web Application Firewall (WAF) is designed to protect web applications (typically on ports 80/443) by inspecting HTTP/HTTPS traffic for web-based attacks like SQL injection or cross-site scripting. A WAF provides no protection for the RDP service. Since the server is external-facing, the RDP port is directly exposed to the internet, significantly increasing the likelihood of exploitation.

Correct Option

D. The risk would increase because the host is external facing.
Risk is a function of threat, vulnerability, and impact. The vulnerability (a flaw in the RDP service) is present on a system directly accessible from the internet. This high-threat environment, where attackers can directly probe and attempt to exploit the vulnerability, greatly increases the overall risk.

The existing security control (the WAF) is ineffective against this specific threat because it does not monitor or filter RDP traffic on port 3389. Therefore, the risk is substantially elevated due to the host's exposure.

Incorrect Options

A. The risk would not change because network firewalls are in use.
This is incorrect. The scenario does not state that a network firewall is blocking port 3389; in fact, the vulnerability was scanned and identified over that port, implying it is open and accessible. Even if a firewall were present, assuming the risk is unchanged ignores the critical factor of the server's external-facing nature.

B. The risk would decrease because RDP is blocked by the firewall.
This is factually wrong based on the evidence. The scan successfully identified the vulnerability over port 3389, proving that RDP is not blocked. The vulnerability would be unreachable if the port were closed, but it is not.

C. The risk would decrease because a web application firewall is in place.
This misinterprets the function of a WAF. A WAF is a specialized control for web application traffic. It provides zero protection for network services like RDP. Therefore, its presence does not mitigate the risk associated with this specific vulnerability at all.

Reference
NIST Special Publication 800-30, Guide for Conducting Risk Assessments: This guide defines risk as a function of the likelihood of a threat event exploiting a vulnerability and the resulting impact. The external-facing nature of the server greatly increases the likelihood of a threat event, while the lack of a relevant security control (the WAF is not applicable) fails to reduce that likelihood, resulting in increased overall risk.

Summary
Root cause analysis (RCA) is a systematic process for identifying the fundamental, underlying reason for an incident. After an attacker has been blocked and the immediate threat is contained, the goal of RCA is to discover the initial point of compromise and the sequence of events that led to the breach. This requires a detailed forensic review of historical data, such as system and application logs, to trace the attacker's actions back to their origin.

Correct Option

C. Review the log files that record all events related to client applications and user access.
Log files provide an objective, chronological record of all activity on a system. To perform a root cause analysis, the analyst must trace the attack back to its origin.

By meticulously reviewing authentication logs, database query logs, and network connection logs, the analyst can identify the initial vulnerability exploited (e.g., a SQL injection attack, stolen credentials), the first system compromised, and the lateral movement taken to reach the database. This evidence-based approach is the core of determining the "root cause."

Incorrect Options

A. Document the incident and any findings related to the attack for future reference.
Documentation is a critical step within the incident response process and occurs after the investigation and analysis are complete. It is an output of the RCA, not the primary activity for determining the root cause itself.

B. Interview employees responsible for managing the affected systems.
While interviewing system administrators can provide valuable context and clues, it is a subjective source of information. The primary method for technical root cause analysis must be the analysis of hard evidence from logs and system artifacts to objectively determine what happened.

D. Identify the immediate actions that need to be taken to contain the incident and minimize...
This option describes the containment and eradication phases of incident response, which occur before a full root cause analysis can be safely conducted. The RCA typically happens during the post-incident activity phase, after the immediate threat has been neutralized.

Reference
NIST Special Publication 800-61 (Computer Security Incident Handling Guide): The guide outlines the incident response lifecycle. The "Post-Incident Activity" phase is where root cause analysis is performed. It emphasizes the importance of a "lessons-learned" meeting, which is fueled by the findings from a detailed review of evidence, such as "monitoring records and log files," to determine how the incident occurred.

Summary
Key Performance Indicators (KPIs) for a cybersecurity program are metrics that measure the effectiveness and efficiency of security operations. The specific metric that quantifies the duration between when a security threat first occurs and when it is discovered by the security team is a fundamental measure of detection capability. This metric directly answers the management question of how long threats remain unnoticed.

Correct Option

C. Mean time to detect
Mean Time to Detect (MTTD) is a standard cybersecurity metric that measures the average time taken to identify a security threat from the moment it begins. A lower MTTD indicates a more efficient Security Operations Center (SOC) with robust monitoring and alerting systems. Reporting this monthly shows trends in the organization's ability to quickly discover threats, which is critical for minimizing potential damage.

Incorrect Options

A. Employee turnover
This is a Human Resources metric that measures staff retention. While high turnover in the security team could indirectly impact MTTD, it does not directly measure how long a threat goes unnoticed and is not a standard cybersecurity KPI for threat detection.

B. Intrusion attempts
This metric counts the number of attacks blocked at the perimeter (e.g., by a firewall or IPS). It measures the volume of attack attempts but provides no information about threats that were not blocked and entered the environment, which is what the "unnoticed" timeframe refers to.

D. Level of preparedness
This is a subjective or composite assessment of the organization's security posture, often based on audits or tabletop exercises. While important, it is not a quantifiable, time-based metric that shows how long actual threats remain undetected in the live environment.

Reference
NIST Special Publication 800-55, Performance Measurement Guide for Information Security: This publication provides a framework for developing information security metrics. It categorizes metrics based on their purpose. MTTD is an example of a "management" or "impact" metric that measures the effectiveness of the detection process, aligning directly with the goal of identifying how long threats go unnoticed.

Summary
The software controlling centrifugal pumps at a power plant is a safety-critical system where a failure could have catastrophic consequences. The necessary level of assurance must be extremely high, requiring mathematical certainty that the software behaves exactly as specified under all conditions. Formal methods provide this highest level of assurance by using mathematical models and logical reasoning to verify the software's correctness, leaving no room for undetected errors that might be missed by testing or review.

Correct Option

D. Formal methods
Formal methods use mathematical techniques (such as model checking and theorem proving) to specify and verify the behavior of a software system. The code and its requirements are expressed as precise mathematical models.

This allows for exhaustive analysis that proves, with mathematical certainty, the absence of entire classes of errors and that the software will behave as intended under all possible conditions. This level of rigor is required for the highest levels of safety assurance in industries like nuclear power, aviation, and medical devices.

Incorrect Options

A. Containerization
Containerization is a deployment and isolation technology (e.g., Docker). It packages an application and its dependencies, but it does nothing to verify the logical correctness or safety of the embedded software itself. It is irrelevant to providing functional assurance.

B. Manual code reviews
While manual reviews are a valuable software engineering practice, they are inherently human-dependent and prone to overlooking complex logical errors. They cannot provide the exhaustive, mathematical proof of correctness required for life-critical systems like those in a power plant.

C. Static and dynamic analysis
These are excellent for finding many bugs and vulnerabilities. Static analysis checks code without running it, while dynamic analysis tests it during execution. However, they are not exhaustive. They can prove the presence of bugs but cannot prove their absence with absolute certainty, which is the standard needed for this context.

E. D
This appears to be an incomplete or erroneous option and does not represent a valid software assurance technique.

Reference
National Institute of Standards and Technology (NIST) - Formal Methods: NIST publications on software verification recognize formal methods as the highest-assurance approach. They state that formal methods can "provide a mathematical proof that a system satisfies certain properties," which is essential for certifying safety-critical systems where failure is not an option. This aligns with standards in industries like nuclear power (e.g., IEC 61508).

Summary
The scenario describes a threat actor who has already gathered information (from technical forums) and is now in the process of creating and refining a malicious tool. The specific actions of compiling a downloader and testing it against security controls are focused on creating the operational weapon to be used in the attack. This stage involves coupling the malicious payload with an exploit or creating a delivery mechanism and ensuring it is effective and undetectable.

Correct Option

D. Weaponization
The Weaponization stage occurs when a threat actor takes a discovered vulnerability and pairs it with a malicious payload to create a deliverable weapon. In this case, the actor is "compiling" the downloader (creating the weapon) and "testing it to ensure it will not be detected" (refining the weapon to bypass defenses). This stage is distinct from reconnaissance (information gathering) and occurs before the weapon is delivered to the victim. The actions described are the core activities of weaponization: building and validating the attack tool.

Incorrect Options

A. Delivery
The Delivery stage involves transmitting the weapon to the victim (e.g., via email attachment, malicious link, or USB drive). The scenario describes the actor preparing the weapon, not yet sending it to the target organization.

B. Reconnaissance
Reconnaissance is the initial research phase where the attacker harvests email addresses, learns about the target's infrastructure, and identifies potential vulnerabilities. While the actor used OSINT from forums, the described actions (compiling and testing) are active development steps that occur after the initial reconnaissance is complete.

C. Exploitation
Exploitation is the stage where the weapon is delivered and triggered to exploit a vulnerability on the victim's system. The scenario describes the preparation and testing of the weapon in a lab environment, not the act of exploiting a target system.

Reference
Lockheed Martin Cyber Kill Chain®: The official framework defines the Weaponization phase as the process where a threat actor creates a malicious payload (like a downloader) and couples it with an exploit into a deliverable weapon. The testing of the weapon against security controls to avoid detection is a common step within this phase to ensure the attack will be successful.

Summary
Operational Technology (OT) networks, especially those with fragile or legacy equipment like Programmable Logic Controllers (PLCs), are highly sensitive to any unexpected network traffic. Active vulnerability scans, which send probes and packets to devices, can cause these devices to malfunction, crash, or halt a manufacturing process. Passive scanning observes network traffic without interacting with devices, providing intelligence without the risk of disrupting critical operations.

Correct Option

C. Using passive instead of active vulnerability scans
Passive scanning uses a network tap or span port to silently monitor and analyze all network traffic. It identifies devices, services, and potential vulnerabilities by listening to regular communications and banner information without sending any packets to the devices.

This method is non-intrusive and carries zero risk of disrupting the fragile or legacy equipment. It allows the consultant to gather crucial security assessment data while fully adhering to the prime directive in OT environments: "First, do no harm."

Incorrect Options

A. Employing Nmap Scripting Engine scanning techniques
The Nmap Scripting Engine (NSE) is a powerful tool for active reconnaissance that can perform aggressive checks. Sending such scripts to fragile OT devices is very likely to cause them to hang, fault, or behave unpredictably, making this a dangerous choice.

B. Preserving the state of PLC ladder logic prior to scanning
While backing up PLC logic is a good general practice, it does not prevent the scan from causing the disruption in the first place. It is a reactive measure for recovery, not a proactive measure for preventing harm during the assessment.

D. Running scans during off-peak manufacturing hours
Scanning during a maintenance window reduces the impact of a potential outage but does not eliminate the risk of causing one. The fragile equipment can still be damaged or forced into a fault state regardless of the time of day. The goal is to avoid disruption entirely, not just to schedule it.

Reference
CISA (Cybersecurity and Infrastructure Security Agency) - Assessing Cybersecurity in Operational Technology: CISA guidelines and best practices for OT environments consistently recommend passive asset discovery and vulnerability assessment as the primary method to avoid impacting system availability and integrity. They explicitly warn that active scanning can disrupt control processes.

Summary
The core problem is a lack of awareness and formal acknowledgment of the security policy by new employees. To enforce accountability, there must be a verifiable and documented record that each employee has received, understood, and agreed to abide by the company's security rules. An email or verbal confirmation lacks the formality and legal weight to serve as a strong foundation for accountability or potential disciplinary action.

Correct Option

D. All new employees must sign a user agreement to acknowledge the company security policy.
A signed user agreement provides a tangible, legal record of acknowledgment. It formalizes the employee's responsibility and creates a clear basis for accountability. If a policy violation occurs later, the organization can point to the signed document as evidence that the employee was made aware of the rules and agreed to follow them. This strengthens the organization's position for enforcing consequences and is a standard best practice in security awareness and compliance.

Incorrect Options

A. Human resources must email a copy of a user agreement to all new employees
While this ensures the policy is sent, it does not verify that the employee has received, read, or understood it. There is no mechanism for acknowledgment or accountability. An email alone is easily ignored or forgotten.

B. Supervisors must get verbal confirmation from new employees indicating they have read the user agreement.
Verbal confirmation is informal and leaves no durable record. It is subject to memory lapses and "he said, she said" disputes. It does not provide the reliable, documented proof required to enforce accountability effectively.

C. All new employees must take a test about the company security policy during the orientation process.
A test is an excellent tool for ensuring comprehension, which is a separate goal. However, a test does not inherently constitute a formal agreement to abide by the policy. An employee could pass a test but later claim they never formally agreed to be bound by the rules. The signed agreement is the foundation for accountability.

Reference
NIST Special Publication 800-50, Building an Information Technology Security Awareness and Training Program: This guide emphasizes that a key component of an effective program is ensuring personnel "sign an acknowledgment form stating they have read and understand the rules of behavior." This formal acknowledgment is critical for establishing individual accountability for adhering to security policies.