CS0-003 CompTIA CyberSecurity Analyst CySA+ Certification Exam Free Practice Exam Questions (2025 Updated)

The user has become an insider threat by downloading software that contains malware onto a computer that eventually infects numerous other systems. An insider threat is a person or entity that has legitimate access to an organization’s systems, networks, or resources and uses that access to cause harm or damage to the organization. An insider threat can be intentional or unintentional, malicious or negligent, and can result from various actions or behaviors, such as downloading unauthorized software, violating security policies, stealing data, sabotaging systems, or collaborating with external attackers.

An incident response plan (IRP) is a document that defines the roles and responsibilities, procedures, and guidelines for responding to a security incident. It helps the security team to act quickly and effectively, minimizing the impact and cost of the incident. An IRP should specify who should conduct the next steps following a security event, such as containment, eradication, recovery, and analysis12. References: CompTIA CySA+ CS0-003 Certification Study Guide, page 362; 6 Incident Response Steps to Take After a Security Event, section 2.

The described behavior(pivoting across network segments, targeting domain servers, and exfiltrating data to an unknown location)is characteristic of anadvanced persistent threat (APT), often linked tonation-state actors​.

Option A (Hacktivist)attackers typically engage indefacements or disruptionrather thanstealthy exfiltration.

Option B (Zombie)refers tocompromised hosts in a botnet, but botnets do not usually pivot across networks.

Option C (Insider threat)could involve unauthorized access, but the traffic pattern suggests anexternalattacker withlateral movementtechniques.

Thus,D is the correct answer, asnation-state actors often use sophisticated tactics, including data exfiltration and network pivoting​.

Using aregular expression (regex)to search email logs is the most efficient and scalable way to identify patterns in phishing URLs. Phishing campaigns often use consistent URL formats across different domains. Regex allows administrators to define flexible patterns to match these URLs even when the domains vary. This is significantly more effective than relying on user reports or less granular tools like firewall logs for such cases.

Header analysis is the technique of examining the metadata of an email, such as the sender, recipient, date, subject, and routing information. It can help to identify the source of a malicious email by revealing the IP address and domain name of the originator, as well as any spoofing or redirection attempts. References: CompTIA CySA+ Study Guide: Exam CS0-003, 3rd Edition, Chapter 6, page 240; CompTIA CySA+ CS0-003 Certification Study Guide, Chapter 6, page 249.

The analyst should focus on the impact of the events in order to move the incident forward. Impact is the measure of the potential or actual damage caused by an incident, such as data loss, financial loss, reputational damage, or regulatory penalties. Impact can help the analyst prioritize the events that need to be investigated based on their severity and urgency, and allocate the appropriate resources and actions to contain and remediate them. Impact can also help the analyst communicate the status and progress of the incident to the stakeholders and customers, and justify the decisions and recommendations made during the incident response12. Vulnerability score, mean time to detect, and isolation are all important metrics or actions for incident response, but they are not the main focus for moving the incident forward. Vulnerability score is the rating of the likelihood and severity of a vulnerability being exploited by a threat actor. Mean time to detect is the average time it takes to discover an incident. Isolation is the process of disconnecting an affected system from the network to prevent further damage or spread of the incident34 . References: Incident Response: Processes, Best Practices & Tools - Atlassian, Incident Response Metrics: What You Should Be Measuring, Vulnerability Scanning Best Practices, How to Track Mean Time to Detect (MTTD) and Mean Time to Respond (MTTR) to Cybersecurity Incidents, [Isolation and Quarantine for Incident Response]

The threat was detected from the time the emails were sent at 8:30 a.m. to when the recipients started alerting the organization’s help desk about the email at 8:45 a.m., taking a total of 15 minutes. The detection time is the time elapsed between the occurrence of an incident and its discovery by the security team . The other options are either too short or too long based on the given information. References: : Detection Time : Incident Response Metrics: Mean Time to Detect and Mean Time to Respond

A prioritized list of critical systems defined by executive leadership is the best option to use to develop a business continuity plan. A business continuity plan (BCP) is a system of prevention and recovery from potential threats to a company. The plan ensures that personnel and assets are protected and are able to function quickly in the event of a disaster1. A BCP should include a business impact analysis, which identifies the critical systems and processes that are essential for the continuity of the business operations, and the potential impacts of their disruption2. The executive leadership should be involved in defining the critical systems and their priorities, as they have the strategic vision and authority to make decisions that affect the whole organization3. A diagram of all systems and interdependent applications, a repository for all the software used by the organization, and a configuration management database in print at an off-site location are all useful tools for documenting and managing the IT infrastructure, but they are not sufficient to develop a comprehensive BCP that covers all aspects of the business continuity4. References: What Is a Business Continuity Plan (BCP), and How Does It Work?, Business continuity plan (BCP) in 8 steps, with templates, Business continuity planning | Business Queensland, Understanding the Essentials of a Business Continuity Plan

The NTP configuration on each system should be checked first, as it is essential for ensuring accurate and consistent time stamps across different systems. NTP is the Network Time Protocol, which is used to synchronize the clocks of computers over a network. NTP uses a hierarchical system of time sources, where each level is assigned a stratum number. The most accurate time sources, such as atomic clocks or GPS receivers, are at stratum 0, and the devices that synchronize with them are at stratum 1, and so on. NTP clients can query multiple NTP servers and use algorithms to select the best time source and adjust their clocks accordingly1. If the NTP configuration is not consistent or correct on each system, the time stamps of the logs and events may differ, making it difficult to correlate incidents across different systems. This can affect the security analysis and correlation of events, as well as the compliance and auditing of the network23. References: How the Windows Time Service Works, Time Synchronization - All You Need To Know, What is SIEM? | Microsoft Security

An incident response plan is a set of predefined procedures and guidelines that an organization follows when faced with a security breach or attack. An incident response plan helps to ensure that the organization can quickly and effectively contain, analyze, eradicate, and recover from the incident, as well as prevent or minimize the damage and impact to the business operations, reputation, andcustomers. An incident response plan also defines the roles and responsibilities of the incident response team, the communication channels and protocols, the escalation and reporting procedures, and the tools and resources available for the incident response.

By following the company’s incident response plan, the administrator can ensure that they are following the best practices and standards for handling a security incident, and that they are coordinating and collaborating with the relevant stakeholders and authorities. Following the company’s incident response plan can also help to avoid or reduce any legal, regulatory, or contractual liabilities or penalties that may arise from the incident.

The other options are not as effective or appropriate as following the company’s incident response plan. Informing the internal incident response team (A) is a good step, but it should be done according to the company’s incident response plan, which may specify who, when, how, and what to report. Reviewing the lessons learned for the best approach © is a good step, but it should be done after the incident has been resolved and closed, not during the active response phase. Determining when the access started (D) is a good step, but it should be done as part of the analysis phase of the incident response plan, not before following the plan.

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​.

Defense evasion is the technique of avoiding detection or prevention by security tools or mechanisms. In this case, the freeware program is likely a malware that generates random DNS queries to communicate with a command and control server or exfiltrate data. The command Add-MpPreference -ExclusionPath '%Program Filest\ksysconfig' is used to add an exclusion path to Windows Defender, which is a built-in antivirus software, to prevent it from scanning the malware folder. References: CompTIA CySA+ Study Guide: Exam CS0-003, 3rd Edition, Chapter 5, page 204; CompTIA CySA+ CS0-003 Certification Study Guide, Chapter 5, page 212. pr

XDR logs will confirm the malware infection because XDR is a system that collects and analyzes data from multiple sources, such as endpoints, networks, cloud applications, and email security, to detect and respond to advanced threats12. XDR can provide a comprehensive view of the attack chain and the context of the malware infection. Firewall logs, IDS logs, and MFA logs are not sufficient to confirm the malware infection, as they only provide partial or indirect information about the network traffic, intrusion attempts, or user authentication. References: Cybersecurity Analyst+ - CompTIA, XDR: definition and benefits for MSPs| WatchGuard Blog, Extended detection and response - Wikipedia

Thechain of custodyis a documented history that tracks how evidence is handled, collected, transported, and preserved at every stage of the forensic investigation. If a gap exists in the record of who transferred or accessed the evidence, it could call into question the integrity and admissibility of the evidence​.

Validating data integrity (Option A)refers to ensuring that the forensic image is identical to the original data, often using cryptographic hashing, but it does not address procedural gaps in documentation.

Preservation (Option B)involves protecting the original evidence from modification or loss but does not include logging transfers of custody.

Legal hold (Option C)refers to a requirement to preserve data for legal proceedings, which is different from tracking evidence handling​.

Thus, the correct answer isD, as chain of custody directly relates to tracking who had access to the evidence and when​.

Security Orchestration, Automation, and Response (SOAR) can help the SOC analyst reduce the number of alarms by automating the process of removing duplicates and managing security alerts more efficiently. SOAR platforms enable security teams to define, prioritize, and standardize response procedures, which helps in reducing the workload and improving the overall efficiency of incident response by handling repetitive and low-level tasks automatically.

A mean time to remediate (MTTR) is a metric that measures how long it takes to fix a vulnerability after it is discovered. A MTTR of 30 days would best protect the organization from the new attacks that are exploited 45 days after a patch is released, as it would ensure that the vulnerabilities are fixed before they are exploited

Isolation is the first step to take after detecting some indicators of compromise (IoCs) of possible ransomware contamination. Isolation prevents the ransomware from spreading to other servers or segments of the network, and allows the security team to investigate and contain the incident. Isolation can be done by disconnecting the infected servers from the network, blocking the malicious traffic, or applying firewall rules12.

The most likely explanation for this traffic pattern is C2 beaconing activity. C2 stands for command and control, which is a phase of the Cyber Kill Chain that involves the adversary attempting to establish communication with a successfully exploited target. C2 beaconing activity is a type of network traffic that indicates a compromised system is sending periodic messages or signals to an attacker’s system using various protocols, such as HTTP(S), DNS, ICMP, or UDP. C2 beaconingactivity can enable the attacker to remotely control or manipulate the target system or network using various methods, such as malware callbacks, backdoors, botnets, or covert channels.

Single Sign-On (SSO) allows users to authenticate once and gain access to multiple applications without needing to re-enter credentials for each one.

It reduces password fatigue, improves security, and streamlines authentication across vendor portals.

Why Not Other Options?

A (API) → APIs facilitate data exchange but do not solve authentication problems.

B (MFA) → Enhances security but still requires multiple logins.

D (VPN) → Secures connections but does not eliminate multiple logins.