CS0-003 Exam Overview
Prepare for the Comptia CS0-003 certification exam
with our comprehensive study guide. This study material contains 483 practice questions
sourced from real exams and expert-verified for accuracy. Each question includes the correct answer
and a detailed explanation to help you understand the material thoroughly.
The CS0-003 exam — CySA+ — is offered by Comptia.
Passing this exam earns you the CompTIA CySA+ credential,
an industry-recognized certification that validates your expertise.
Our study materials were last updated on 2026-02-20 to reflect the
most recent exam objectives and content.
About the CompTIA CySA+
The CompTIA CySA+ is awarded by Comptia
to professionals who demonstrate competence in the skills measured by the CS0-003 exam.
According to the
official Comptia certification page,
this certification validates your ability to work with the technologies covered in the exam objectives.
According to the
Global Knowledge IT Skills and Salary Report,
certified IT professionals earn 15-25% more than their non-certified peers.
Certifications from Comptia are among the most recognized credentials in the IT industry,
with strong demand across enterprise organizations worldwide.
Free Sample — 15 Practice Questions
Preview 15 of 483 questions from the CS0-003 exam.
Try before you buy — purchase the full study guide for all 483 questions with answers and explanations.
Question 125
Which of the following is the best reason to implement an MOU?
A. To create a business process for configuration management
B. To allow internal departments to understand security responsibilities
C. To allow an expectation process to be defined for legacy systems
D. To ensure that all metrics on service levels are properly reported
Show Answer
Correct Answer: B
Explanation:
An MOU is used to formally document mutual understanding between parties, including roles, responsibilities, and expectations. Among the options, allowing internal departments to understand and agree on security responsibilities best reflects the purpose of an MOU. The other options relate to specific operational processes (configuration management, legacy system expectations, or service-level metrics) that are more appropriate for policies, procedures, SLAs, or OLAs rather than an MOU.
Question 245
A security analyst receives an alert for suspicious activity on a company laptop. An excerpt of the log is shown below:
Which of the following has most likely occurred?
A. An Office document with a malicious macro was opened.
B. A credential-stealing website was visited.
C. A phishing link in an email was clicked.
D. A web browser vulnerability was exploited.
Show Answer
Correct Answer: A
Explanation:
The log sequence indicates Microsoft Word spawning PowerShell, which is a common execution chain for malicious Office macros. Malicious macros frequently use PowerShell to download or execute additional payloads after a document is opened. This behavior is not typical of normal browsing or credential phishing alone and strongly points to a macro-enabled Office document.
Question 18
Which of the following is the best technical method to protect sensitive data at an organizational level?
A. Deny all traffic on port 8080 with sensitive information on the VLAN.
B. Develop a Python script to review email traffic for PII.
C. Employ a restrictive policy for the use and distribution of sensitive information.
D. Implement a DLP for all egress and ingress of sensitive information on the network.
Show Answer
Correct Answer: D
Explanation:
The question asks for the best *technical* method at an organizational level. A Data Loss Prevention (DLP) solution is specifically designed to technically control, monitor, and prevent unauthorized transmission of sensitive data across the organization, covering network egress/ingress, endpoints, and sometimes data at rest. Option C is administrative, not technical. Options A and B are narrow and insufficient controls. Therefore, D is the best answer.
Question 296
A cybersecurity team has witnessed numerous vulnerability events recently that have affected operating systems. The team decides to implement host-based IPS, firewalls and two-factor authentication. Which of the following does this most likely describe?
A. System hardening
B. Hybrid network architecture
C. Continuous authorization
D. Secure access service edge
Show Answer
Correct Answer: A
Explanation:
The scenario describes implementing host-based IPS, host firewalls, and two-factor authentication on operating systems to reduce vulnerabilities and attack surface. These are classic operating system and endpoint-level security controls associated with system hardening. The other options describe broader architectures or access models (hybrid architecture, continuous authorization, or SASE) rather than direct OS-level protective measures.
Question 185
A Chief Information Security Officer has requested a dashboard to share critical vulnerability management goals with company leadership. Which of the following would be the best to include in the dashboard?
A. KPI
B. MOU
C. SLO
D. SLA
Show Answer
Correct Answer: A
Explanation:
A dashboard for company leadership should present measurable progress toward vulnerability management goals. Key Performance Indicators (KPIs) provide quantifiable metrics such as mean time to remediate critical vulnerabilities or percentage of critical findings closed. MOUs are agreements, while SLOs and SLAs define targets/commitments rather than report performance. Therefore, KPIs are the best fit.
Question 271
Which of the following techniques can help a SOC team to reduce the number of alerts related to the internal security activities that the analysts have to triage?
A. Enrich the SIEM-ingested data to include all data required for triage
B. Schedule a task to disable alerting when vulnerability scans are executing
C. Filter all alarms in the SIEM with low seventy
D. Add a SOAR rule to drop irrelevant and duplicated notifications
Show Answer
Correct Answer: D
Explanation:
The goal is to reduce the number of alerts that analysts must triage, especially those generated by internal security activities. A SOAR platform can automatically suppress, deduplicate, and filter irrelevant alerts before they reach analysts, directly reducing alert volume. Enriching SIEM data improves investigation quality but does not reduce alert count (A). Disabling alerts during scans is risky and not best practice (B). Filtering by low severity may hide important signals and is too blunt (C). Therefore, adding a SOAR rule to drop irrelevant and duplicated notifications is the most effective and appropriate technique.
Question 455
A security analyst is performing vulnerability scans on the network. The analyst installs a scanner appliance, configures the subnets to scan, and begins the scan of the network. Which of the following would be missing from a scan performed with this configuration?
A. Operating system version
B. Registry key values
C. Open ports
D. IP address
Show Answer
Correct Answer: B
Explanation:
With only a scanner appliance deployed and subnets defined, the scan described is a standard unauthenticated network vulnerability scan. Such scans can identify IP addresses, open ports, running services, and often infer operating system versions through fingerprinting. However, registry key values require authenticated access to the host (and are Windows-specific), which is not available in this configuration. Therefore, registry key values would be missing from the scan.
Question 360
Patches for two highly exploited vulnerabilities were released on the same Friday afternoon. Information about the systems and vulnerabilities is shown in the tables below:
Which of the following should the security analyst prioritize for remediation?
A. rogers
B. brady
C. brees
D. manning
Show Answer
Correct Answer: B
Explanation:
Prioritize the externally facing system with a remote code execution vulnerability. An internet-accessible host can be exploited directly without first breaching internal controls, making it the most likely and impactful attack path and a potential pivot for lateral movement. Among the options, brady fits this highest-risk profile.
Question 61
A security manager has decided to form a special group of analysts who participate in both penetration testing and defending the company's network infrastructure during exercises.
Which of the following teams should the group form in order to achieve this goal?
A. Blue team
B. Purple team
C. Red team
D. Green team
Show Answer
Correct Answer: B
Explanation:
Penetration testing is performed by red teams (offensive), while defense is handled by blue teams. A purple team combines and coordinates both functions, enabling analysts to participate in attacking and defending during exercises.
Question 53
Executives want to compare certain metrics from the most recent and last reporting periods to determine whether the metrics are increasing or decreasing. Which of the following would provide the necessary information to satisfy this request?
A. Count level
B. Trending analysis
C. Impact assessment
D. Severity score
Show Answer
Correct Answer: B
Explanation:
The request is to compare metrics between the most recent and prior reporting periods to see whether they are increasing or decreasing. Trending analysis is specifically designed to compare data over time and identify upward or downward patterns, making it the correct choice.
Question 277
A security analyst has received an incident case regarding malware spreading out of control on a customer's network. The analyst is unsure how to respond. The configured EDR has automatically obtained a sample of the malware and its signature. Which of the following should the analyst perform next to determine the type of malware based on its telemetry?
A. Cross-reference the signature with open-source threat intelligence.
B. Configure the EDR to perform a full scan.
C. Transfer the malware to a sandbox environment.
D. Log in to the affected systems and run netstat.
Show Answer
Correct Answer: A
Explanation:
The EDR has already collected the malware sample, its signature, and associated telemetry. The most appropriate next step to determine the malware type is to identify it by comparing the known signature against existing knowledge bases. Cross-referencing with open-source threat intelligence (for example, VirusTotal or other TI feeds) can quickly classify the malware, reveal known behaviors, and provide context for response. A sandbox is more useful when the malware is unknown or no signature/telemetry exists, whereas here identification can be achieved faster through threat intelligence correlation.
Question 358
A virtual web server in a server pool was infected with malware after an analyst used the internet to research a system issue. After the server was rebuilt and added back into the server pool, users reported issues with the website, indicating the site could not be trusted. Which of the following is the most likely cause of the server issue?
A. The server was configured to use SSL to securely transmit data.
B. The server was supporting weak TLS protocols for client connections.
C. The malware infected all the web servers in the pool.
D. The digital certificate on the web server was self-signed.
Show Answer
Correct Answer: D
Explanation:
Browsers report a website as "not trusted" primarily due to certificate validation problems. After the server was rebuilt and reintroduced into the pool, it likely lacked the proper CA‑signed certificate and was using a self‑signed certificate instead. Self‑signed certificates are not trusted by client browsers, which results in trust warnings. Malware spreading or weak TLS settings would not directly cause browsers to label the site as untrusted in this manner.
Question 140
An incident responder was able to recover a binary file through the network traffic. The binary file was also found in some machines with anomalous behavior. Which of the following processes most likely can be performed to understand the purpose of the binary file?
A. File debugging
B. Traffic analysis
C. Reverse engineering
D. Machine isolation
Show Answer
Correct Answer: C
Explanation:
To understand the purpose and functionality of an unknown binary recovered from network traffic and anomalous hosts, analysts would perform reverse engineering. Reverse engineering involves disassembling or decompiling the binary to analyze its logic, capabilities, and potential malicious behavior. Traffic analysis focuses on network flows, machine isolation is a containment step, and file debugging is aimed at fixing software errors rather than understanding an unknown binary’s intent.
Question 250
An analyst discovers unusual outbound connections to an IP that was previously blocked at the web proxy and firewall. Upon further investigation, it appears that the proxy and firewall rules that were in place were removed by a service account that is not recognized. Which of the following parts of the Cyber Kill Chain does this describe?
A. Delivery
B. Command and control
C. Reconnaissance
D. Weaponization
Show Answer
Correct Answer: B
Explanation:
The key indicator is unusual outbound connections to an external IP after proxy and firewall protections were removed. This reflects an established ability for the attacker to communicate externally from the compromised environment. Removing security controls to allow outbound traffic is characteristic of the Command and Control phase, where attackers maintain remote access and manage compromised systems. It is not Reconnaissance (which is information gathering before compromise), nor Delivery or Weaponization.
Question 31
A company suspects a coordinated effort to attack their platform. Web server logs show malicious activity from many different source IP addresses located in different countries. Which of the following will best help a security analyst identify the requests connected to this campaign?
A. Modify the web server logs to include the X-Forwarded-For header.
B. Create a custom SIEM query to integrate threat intel IoCs associated with the threat actor.
C. Enrich the web server request logs with full WHOIS data on all available sources.
D. Add GeoIP location for the source IP addresses to the log entries.
Show Answer
Correct Answer: B
Explanation:
To identify which requests are part of the same coordinated attack campaign, the analyst needs correlation across indicators beyond raw source IPs. Integrating threat intelligence IoCs (e.g., known IPs, domains, user agents, payload patterns, TTPs) into a SIEM query allows grouping and linking disparate requests to the same threat actor or campaign. X-Forwarded-For only reveals original client IPs behind proxies, GeoIP only adds location context, and WHOIS enrichment provides ownership data—none of which effectively correlate activity into a campaign.