CS0-003 CompTIA CyberSecurity Analyst CySA+ Certification Exam Free Practice Exam Questions (2026 Updated)

The best recommendations to prevent an XSS vulnerability from being exploited are to implement a compensating control in the source code and to fix the vulnerability using a virtual patch at the WAF. A compensating control is a technique that mitigates the risk of a vulnerability by adding additional security measures, such as input validation, output encoding, or HTML sanitization. A virtual patch is a rule that blocks or modifies malicious requests or responses at the WAF level, without modifying the application code. These recommendations are effective, efficient, and less disruptive than the other options. References: CompTIA CySA+ Study Guide: Exam CS0-003, 3rd Edition, Chapter 4: Security Operations and Monitoring, page 156; Cross Site Scripting Prevention Cheat Sheet, Section: XSS Defense Philosophy.

Wireshark is a network protocol analyzer that allows analysts to capture and inspect data packets traveling through a network. This makes it ideal for investigating unusual network activity, as it provides detailed insights into the nature and content of network traffic. In this case, Wireshark can help identify potentially malicious packets and understand the nature of the observed traffic. Options A (WAF) and C (EDR) are primarily used for monitoring and protecting web applications and endpoints, respectively, and Nmap (D) is typically used for network discovery and mapping, not detailed traffic analysis. According to CompTIA CySA+, packet analysis tools like Wireshark are invaluable for deep-dive investigations into network anomalies.

Tocapture and analyze network traffic, the two best tools are:

tcpdump (Option A)– A command-line packet capture tool used for network traffic analysis.

Wireshark (Option D)– A GUI-based network packet analysis tool that provides deep inspection capabilities​.

Option B (SIEM)is forlog aggregationand does notcapturetraffic.

Option C (Vulnerability scanner)identifies weaknesses but does notcapturenetwork traffic.

Option E (Nmap)is used for network discovery and port scanning, not capturing traffic.

Option F (SOAR)automates security processes but does not capture traffic.

Thus,A (tcpdump) and D (Wireshark) are correct, asthey are the best tools for capturing and analyzing anomalous network traffic​.

Implementing segmentation with ACLs is the best solution to secure the network. Segmentation is the process of dividing a network into smaller subnetworks, or segments, based on criteria such as function, location, or security level. Segmentation can help improve the network performance, scalability, and manageability, as well as enhance the network security by isolating the sensitive or critical data and systems from the rest of the network. ACLs are Access Control Lists, which are rules or policies that specify which users, devices, or applications can access a network segment or resource, and which actions they can perform. ACLs can help enforce the principle of least privilege, and prevent unauthorized or malicious access to the network segments or resources12. Configuring logging and monitoring to the SIEM, deploying MFA to cloud storage locations, and rolling out an IDS are all good security practices, but they are not the best solution to secure the network. Logging and monitoring tothe SIEM can help detect and analyze the network events and incidents, but they do not prevent them. MFA can help authenticate the users who access the cloud storage locations, but it does not protect the network from attacks or breaches. IDS can help identify and alert the network intrusions, but it does not block them34 . References: Network Segmentation: What It Is and How to Do It Right, What is an Access Control List (ACL)? | IBM, What is SIEM? | Microsoft Security, What is Multifactor Authentication (MFA)? | Duo Security, [What is an Intrusion Detection System (IDS)? | IBM]

Key pair authentication is a method of using a public and private key to securely access cloud resources, such as downloading the configuration of assets from a cloud tenancy. Key pair authentication is more secure than user and password or PAM, and does not require an additional factor like MFA.

Using a vendor-provided API to automate pulling logs in real-time is the best option for improving the efficiency of security operations when the financial application does not allow event logging to send to the corporate SIEM. This approach ensures that logs are consistently and promptly integrated into the security monitoring process without manual intervention, enhancing the overall effectiveness of security operations.

The captured traffic shows TCP packets with the Flags [FPU], which indicate that the FIN, PSH, and URG flags are set. This is characteristic of an Nmap Xmas scan. The Xmas scan is a type of port scan that sends packets with these flags set to determine port states based on responses from the target system. This technique is often used in stealth scanning to evade detection by firewalls or IDS/IPS​.

Nikto ' s web scan (B) is used for identifying web server vulnerabilities but does not generate TCP packets with such unusual flags​.

Socat ' s proxying (C) would not exhibit the specific Xmas scan pattern.

Angry IP Scanner (D) is a general-purpose scanner that does not use the TCP flags seen in this capture​.

The key phrase is “analyzes suspicious data after scanning”. Before you can prioritize remediation, you must first ensure the scan results are valid—i.e., determine whether the findings are true positives vs. false positives. That validation step is a core part of vulnerability management because it prevents wasting time remediating issues that do not actually exist and ensures your prioritization decisions are based on accurate findings.

The All-in-One CySA+ CS0-003 guide explicitly states that after receiving vulnerability scan data, the analyst’s review process must focus on validating reported vulnerabilities (true/false positives). It also directly ties this to remediation/prioritization.

Exact extract (All-in-One Exam Guide):

“It is up to the analyst to review and make sense of vulnerability data and findings… The two most important outcomes of the review process are to determine the validity of reported vulnerabilities…”

It further emphasizes the importance of differentiating true positives from false positives for remediation and prioritization:

Exact extract (All-in-One Exam Guide):

“Distinguishing true positives from false positives… can be a tricky part of vulnerability remediation and prioritization.”

So, Option B (determine true/false positives) is the best action specifically to prioritize remediation tasks based on scan results.

Why the other options are not best:

A: Sending to IR may be appropriate if there is evidence of an active incident, but the question is framed as post-scan vulnerability management (not confirmed incident handling). Validation comes first.

C: Tickets and timeframes are important (often driven by SLAs/SLOs), but setting those correctly depends on confirming the findings are real and understanding severity/impact first.

D: Compensating controls and risk register entries are appropriate when remediation is not immediately feasible, but again you must confirm validity and then prioritize based on risk/impact.

References (CompTIA CySA+ CS0-003 documents / study guides used):

Mya Heath et al., CompTIA CySA+ All-in-One Exam Guide (CS0-003): validating vulnerability scan results; true/false positives; link to remediation prioritization

Conducting regular code reviews using OWASP best practices is the most effective action to reduce risks associated with the application development. Code reviews are a systematic examination of the source code of an application to detect and fix errors, vulnerabilities, and weaknesses that may compromise the security, functionality, or performance of the application. Code reviews can help to improve the quality and security of the code, as well as to identify and remediate common security risks, such as insufficient logging capabilities. OWASP (Open Web Application Security Project) is a global nonprofit organization that provides free and open resources, tools, standards, and best practices for web application security. OWASP best practices for logging include following a common loggingformat and approach, logging relevant security events and data, protecting log data from unauthorized access or modification, and using log analysis and monitoring tools to detect and respond to security incidents. By following OWASP best practices for logging, developers can ensure that their web applications have sufficient and effective logging capabilities that can help to prevent, detect, and mitigate security threats.

The first action that the analyst should take in this case is to clone the virtual server for forensic analysis. Cloning the virtual server involves creating an exact copy or image of the server’s data and state at a specific point in time. Cloning the virtual server can help preserve and protect any evidence or information related to the security incident, as well as prevent any tampering, contamination, or destruction of evidence. Cloning the virtual server can also allow the analyst to safely analyze and investigate the incident without affecting the original server or its operations.

The issue is that laptops are often off-network (traveling), causing inaccurate network-scan metrics and slower detection. The best way to reduce MTTD (mean time to detect vulnerabilities) for roaming endpoints is agent-based scanning, because agents run continuously on endpoints and can still scan/report results even when devices are not connected to the corporate network.

Exact extract (All-in-One Exam Guide):

“Because the agents run continuously on each host, mobile devices can still be scanned even when they are not connected to the corporate network.”

It further emphasizes suitability for mobile devices:

Exact extract (All-in-One Exam Guide):

“agent-based (or serverless) vulnerability scans are typically better for scanning mobile devices.”

And Sybex Practice Tests directly supports this scenario (traveling sales laptops) by selecting agent-based scanning as best for accurate config visibility on traveling laptops:

Exact extract (Sybex Practice Tests):

“…most accurate view of configuration issues on laptops belonging to traveling salespeople. Which technology will work best…? A. Agent-based scanning”

Why the other options don’t solve the “traveling laptops” problem:

B (credentialed scans): improves depth/accuracy when the device is reachable, but does nothing when laptops are offline/not on the network.

C (more frequent network scans): still misses devices that aren’t connected.

D (increase runtime): waiting longer doesn’t reduce MTTD; it just delays reporting and still won’t scan an off-network device.

References (CompTIA CySA+ CS0-003 documents / study guides used):

Mya Heath et al., CompTIA CySA+ All-in-One Exam Guide (CS0-003): agents scan continuously; mobile devices can be scanned off-network; agent-based better for mobile devices

Chapple/Seidl, CompTIA CySA+ Practice Tests (CS0-003): agent-based scanning best for traveling laptop scanning accuracy

An important aspect that should be included in the lessons-learned step after an incident is to identify any improvements or changes in the incident response plan or procedures. The lessons-learned step is a process that involves reviewing and evaluating the incident response activities and outcomes, as well as identifying and documenting any strengths, weaknesses, gaps, or best practices. Identifying any improvements or changes in the incident response plan or procedures can help enhance the security posture, readiness, or capability of the organization for future incidents

A CASB (Cloud Access Security Broker) is a security solution that acts as an intermediary between cloud users and cloud providers, and monitors and enforces security policies for cloud access and usage. A CASB can help organizations protect their data and applications in the cloud from unauthorized or malicious access, as well as comply with regulatory standards and best practices. A CASB can also provide visibility, control, and analytics for cloud activity, and identify and mitigate potential threats12

The other options are not correct. DMARC (Domain-based Message Authentication, Reporting and Conformance) is an email authentication protocol that helps email domain owners prevent spoofing and phishing attacks by verifying the sender’s identity and instructing the receiver how to handle unauthenticated messages34 SIEM (Security Information and Event Management) is a security solution that collects, aggregates, and analyzes log data from various sources across an organization’s network, such as applications, devices, servers, and users, and provides real-time alerts, dashboards, reports, and incident response capabilities to help security teams identify and mitigate cyberattacks56 PAM (Privileged Access Management) is a security solution that helps organizations manage and protect the access and permissions of users, accounts, processes, and systems that have elevated or administrative privileges. PAM can help prevent credential theft, data breaches, insider threats, and compliance violations by monitoring, detecting, and preventing unauthorized privileged access to critical resources78

The MITRE ATT & CK framework is widely used for tracking and categorizing Tactics, Techniques, and Procedures (TTPs) of adversaries. TTPs help analysts understand the behaviors and methods attackers employ during incidents, making this framework particularly useful in SIEM dashboards for correlating and identifying threats. While the other options (OSSTMM, Diamond Model, OWASP) offer various security methodologies, MITRE ATT & CK is specifically focused on documenting adversary behaviors, making it the best fit here. CompTIA CySA+ often emphasizes MITRE ATT & CK for mapping and understanding threat behaviors in incident response.

Before taking any action, the SOC analyst should first verify if the Indicators of Compromise (IoC) and Tactics, Techniques, and Procedures (TTPs) reported are relevant to the organization’s environment. This involves checking if the vulnerable application or version is actually in use. As per CompTIA’s CySA+ guidelines, relevance verification helps in prioritizing resources and response actionseffectively, ensuring that time is not wasted on threats that do not impact the organization. Options A, B, and D are important subsequent steps if the threat is deemed relevant.

Implementing a central place to manage IT assets is the best solution to decrease the inconsistencies regarding versions and patches in the existing infrastructure. A central place to manage IT assets, such as a configuration management database (CMDB), can help the vulnerability assessment team to have an accurate and up-to-date inventory of all the hardware and software components in the network, as well as their relationships and dependencies. A CMDB can also track the changes and updates made to the IT assets, and provide a single source of truth for the vulnerability assessment team and other teams to compare and verify the versions and patches of the infrastructure12. Implementing credentialed scanning, changing from a passive to an active scanning approach, and performing agentless scanning are all methods to improve the vulnerability scanning process, but they do not address the root cause of the inconsistencies, which is the lack of a central place to manage IT assets3. References: What is a Configuration Management Database (CMDB)?, How to Use a CMDB to Improve Vulnerability Management, Vulnerability Scanning Best Practices

Deduplication is a process that involves removing any duplicate or redundant data or information from a data set or source. Deduplication can help consolidate several threat intelligence feeds by eliminating any overlapping or repeated indicators of compromise (IoCs), alerts, reports, or recommendations. Deduplication can also help reduce the volume and complexity of threat intelligence data, as well as improve its quality, accuracy, or relevance.

The string provided ispercent-encoded text, commonly used toobfuscate URLs. When decoded, it translates towww.ice-ptic.com. Such encoding is used tobypass email security filtersandspam detectors, making the malicious link appear as benign or unreadable to the automated scanners.

Option Ais incorrect: The string does not match JavaScript shellcode formats.

Option CandDare unlikely and unrelated to the actual behavior.

?Reference:

CySA+ All-in-One Exam Guide by Mya Heath– Chapter 4, Obfuscated Links

CompTIA Exam Objectives: 1.2 – Indicators of Malicious Activity

The analyst should review PID 768 first because it is the parent process of another suspicious process (PID 1100) and it is also highly suspicious itself due to its unexpected file path.

Why PID 768 is the best first process to review

Path anomaly (strong IoC): Legitimate Windows binaries like calc.exe and cmd.exe are normally found in trusted OS directories (e.g., C:\Windows\System32\). In the table, both CALC.exe and CMD.exe appear in a user’s Documents folder (C:\Users\JDoe\Documents\...). That is a classic sign of masquerading (a malicious binary using a legitimate-sounding name). The All-in-One guide explicitly describes how attackers disguise malicious processes by using legitimate-sounding names and mimicking system processes.

Parent-child relationship (investigation priority): PID 1100 (Documents\CMD.exe) is suspicious, but it is a child of PID 768 (Documents\CALC.exe). Investigating the parent first helps you understand what spawned the suspicious child, what activity preceded it, and whether PID 768 is the root of the execution chain. The All-in-One guide highlights that analysts should examine process parent-child relationships and investigate unexpected dependencies as a way to detect malicious activity:Exact extract (All-in-One Exam Guide): “Analyze process dependencies Examine process parent-child relationships and investigate any unexpected or unusual dependencies that may indicate malicious activity.” It also emphasizes monitoring grandparent/parent/child relationships to detect deviations from normal process hierarchies:Exact extract (All-in-One Exam Guide): “Monitoring the relationships between processes, particularly grandparent, parent, and child relationships, can be a valuable method for detecting unusual activity.”

Abused/LOLBIN context: cmd.exe is a commonly abused Windows utility in attacks. The Sybex Study Guide notes that attackers often abuse built-in tools and that abnormal OS process behavior involving tools like cmd.exe can indicate compromise:Exact extract (Sybex Study Guide): “For Windows systems, a handful of built-in tools are most commonly associated with attacks like these, including cmd.exe…”

Why the other options are less correct

A (533) and B (740) are running from C:\Windows\System32\... which is the expected location for legitimate Windows binaries in normal circumstances, so they’re less suspicious than the copies running from a user Documents folder.

D (1100) is suspicious, but it is a child of PID 768. Investigating 768 first helps determine the origin and execution chain that led to the suspicious cmd instance.

References (CompTIA CySA+ CS0-003 documents / study guides used):

Mya Heath et al., CompTIA CySA+ All-in-One Exam Guide (CS0-003): parent/child process dependency analysis; process hierarchy monitoring; masquerading techniques

Mike Chapple & David Seidl, CompTIA CySA+ Study Guide (CS0-003): abnormal OS process behavior; cmd.exe commonly associated with attacks