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

An Office document with a malicious macro was opened is the most likely explanation for the suspicious activity on the company laptop, as it reflects the common technique of using macros to execute PowerShell commands that download and run malware. A macro is a piece of code that canautomate tasks or perform actions in an Office document, such as a Word file or an Excel spreadsheet. Macros can be useful and legitimate, but they can also be abused by threat actors to deliver malware or perform malicious actions on the system. A malicious macro can be embedded in an Office document that is sent as an attachment in a phishing email or hosted on a compromised website. When the user opens the document, they may be prompted to enable macros or content, which will trigger the execution of the malicious code. The malicious macro can then use PowerShell, which is a scripting language and command-line shell that is built into Windows, to perform various tasks, such as downloading and running malware from a remote URL, bypassing security controls, or establishing persistence on the system. The log excerpt shows that PowerShell was used to download a string from a URL using the WebClient.DownloadString method, which is a common way to fetch and execute malicious code from the internet. The log also shows that PowerShell was used to invoke an expression (iex) that contains obfuscated code, which is another common way to evade detection and analysis. The other options are not as likely as an Office document with a malicious macro was opened, as they do not match the evidence in the log excerpt. A credential-stealing website was visited is possible, but it does not explain why PowerShell was used to download and execute code from a URL. A phishing link in an email was clicked is also possible, but it does not explain what happened after the link was clicked or how PowerShell was involved. A web browser vulnerability was exploited is unlikely, as it does not explain why PowerShell was used to download and execute code from a URL.

The Diamond Model of Intrusion Analysis focuses on understanding the relationships between the adversary, their capabilities, infrastructure, and victim. It provides a structured approach to examining how attackers exploit information assets. According to CompTIA CySA+, this model is valuable for detailing attack patterns and understanding the infrastructure attackers use. The other options, like Structured Threat Information Expression (A) and OWASP Testing Guide (B), address threat data sharing and web application testing, respectively, while the Open Source Security Testing Methodology Manual (OSSTMM) (C) covers general security testing procedures.

The given firewall logs indicatehigh outbound traffic with low IP reputation, sustained over time, which is a strongindicator of cryptomining activity​.

Option A (Anomalous activity)is a general term but does not specifywhythe activity is suspicious.

Option B (Bandwidth saturation)occurs when network traffic is overwhelming, but cryptomining typicallyuses CPU/GPU powerrather than overwhelming bandwidth.

Option D (Denial of service - DoS)would result incontinuous large requests, but cryptomining generatesconsistent, high-bandwidth outbound trafficrather than bursts of large requests.

Thus,C is the correct answer, as cryptomininggenerates unusual outbound network activity from internal hosts to mining pools​.

A signal-shielded bag and a tamper-evident seal are tools that can be used to maintain the integrity of the mobile phone while it is transported. A signal-shielded bag prevents the phone from receiving orsending any signals that could compromise the data or evidence on the device. A tamper-evident seal ensures that the phone has not been opened or altered during the transportation. References: Mobile device forensics, Section: Acquisition

The first action that should be completed to remediate the findings is to perform proper sanitization on all fields. Sanitization is a process that involves validating, filtering, or encoding any user input or data before processing or storing it on a system or application. Sanitization can help prevent various types of attacks, such as cross-site scripting (XSS), SQL injection, or command injection, that exploit unsanitized input or data to execute malicious scripts, commands, or queries on a system or application. Performing proper sanitization on all fields can help address the most critical and common vulnerability found during the vulnerability assessment, which is XSS.

The key goal of the containment stage in an incident response process is to limit further damage from occurring. This involves taking immediate steps to isolate the affected systems or network segments to prevent the spread of the incident and mitigate its impact. Containment strategies can be short-term, to quickly stop the incident, or long-term, to prepare for the eradication and recovery phases.

In case of a phishing attack, it’s crucial to review what actions were taken by the employee and analyze the phishing email to understand its nature and impact.References: CompTIA CySA+ Study Guide: Exam CS0-003, 3rd Edition, Chapter 6, page 246; CompTIA CySA+ CS0-003 Certification Study Guide, Chapter 6, page 255.

Indicators of compromise (IoCs) are pieces of data or evidence that suggest a system or network has been compromised by an attacker or malware. IoCs can include IP addresses, domain names, URLs, file hashes, registry keys, network traffic patterns, user behaviors, or system anomalies. IoCs can be used to detect, analyze, and respond to security incidents, as well as to share threat intelligence with other organizations or authorities. IoCs can produce the data needed for an executive briefing on possible threats to the organization, as they can provide information on the source, nature, scope, impact, and mitigation of the threats.

Risk Acceptance means acknowledging a risk and choosing not to take further action because the cost of mitigation may outweigh the benefits.

It is the last resort when:

The risk is low impact or unlikely to occur.

Other options (mitigation, transfer, avoidance) are not feasible.

Why Not Other Options?

A (Transfer) → Moving risk to a third party (e.g., insurance).

C (Mitigation) → Implementing security controls to reduce risk.

D (Avoidance) → Eliminating the risk entirely (e.g., discontinuing a service).

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

Step 1: Reviewing the Vulnerability Remediation Timeframes

The remediation standards require servers to be patched based on their CVSS score:

CVSS > 9.0: Patch within 7 days

CVSS 7.9 - 9.0: Patch within 14 days

CVSS 5.0 - 7.9: Patch within 30 days

CVSS 0 - 5.0: Patch within 60 days

Step 2: Analyzing the Output Tab

From the Output tab:

Server 192.168.76.5 has a CVSS score of 9.2 for an unsupported Microsoft IIS version, indicating a critical vulnerability requiring a patch within 7 days.

Server 192.168.76.6 has a CVSS score of 7.4 for a missing secure attribute on HTTPS cookies, which falls in the 5.0 - 7.9 range, requiring a patch within 30 days.

Since the question asks for the server to be patched within 14 days, we need to focus on servers with CVSS 7.9 - 9.0:

None of the servers have a CVSS score that falls precisely in the 7.9 - 9.0 range.

However, 192.168.76.5, with a CVSS score of 9.2, has a vulnerability that necessitates a quick response and fits as it must be patched within the shortest timeframe (7 days, which includes 14 days).

The server that fits within a 14-day urgency, based on standard practices, would be 192.168.76.5.

Step 3: Reviewing the Environment Tab

The Environment Tab provides additional context for 192.168.76.5:

It’s in the dev environment, which is internal and not publicly accessible.

MFA is required, indicating security measures are already present.

Step 4: Selecting the Appropriate Technique and Mitigation

For 192.168.76.5, with the Microsoft IIS unsupported version:

Patch; upgrade IIS to the current release is the most suitable option, as upgrading IIS will resolve the unsupported software vulnerability by bringing it up-to-date with supported versions.

This technique addresses the root cause, which is the unpatched, outdated software.

Summary

Server to be patched within 14 calendar days: 192.168.76.5

Appropriate technique and mitigation: Patch; upgrade IIS to the current release

This approach ensures that the most critical vulnerabilities are addressed promptly, maintaining security compliance.

Log entry 4 shows an attempt to exploit the zero-day command injection vulnerability by appending a malicious command (;cat /etc/passwd) to the end of a legitimate request (/cgi-bin/index.cgi?name=John). This command would try to read the contents of the /etc/passwd file, which contains user account information, and could lead to further compromise of the system. The other log entries do not show any signs of command injection, as they do not contain any special characters or commands that could alter the intended behavior of the application. Official References:

https://www.imperva.com/learn/application-security/command-injection/

https://www.zerodayinitiative.com/advisories/published/

Risk scoringis the best method for prioritizing patching, as it considers factors likeCVSS severity, exploitability, asset criticality, and business impact​.

Option A (Affected hosts)is relevant but does notdetermine prioritywithout a risk assessment.

Option C (Mitigation strategy)is useful but focuses on alternative protections rather than prioritization.

Option D (Annual recurrence)is not a standard method for vulnerability prioritization.

Thus,B is the correct answer, asrisk scores allow organizations to prioritize patching efforts effectively​.

AUSB drop attackis acommon method for delivering ransomware, where an attacker leaves infected USB drives in strategic locations,tricking employees into plugging them into corporate devices​.

Option B (LFI - Local File Inclusion)exploitsweb applications, but the scenario lacksnetwork intrusion indicators.

Option C (Cross-site request forgery - CSRF)is used forexploiting authenticated web sessions, not ransomware delivery.

Option D (SQL injection)is used fordatabase exploitation, not file encryption malware.

Thus,A (USB drop) is the correct answer, asphysical malware introduction is a known ransomware attack vector​.

Communicating with staff about the official public communication plan is important to avoid unauthorized or inaccurate disclosure of information that could harm the organization’s reputation, security, or legal obligations. It also helps to ensure consistency and clarity of the messages delivered to the public and other stakeholders.

https://resources.sei.cmu.edu/asset_files/Handbook/2021_002_001_651819.pdf

The best action that would allow the analyst to gather intelligence without disclosing information to the attackers is to upload the binary to an air gapped sandbox for analysis. An air gapped sandbox is an isolated environment that has no connection to any external network or system. Uploading the binary to an air gapped sandbox can prevent any communication or interaction between the binary and the attackers, as well as any potential harm or infection to other systems or networks. An air gapped sandbox can also allow the analyst to safely analyze and observe the behavior, functionality, or characteristics of the binary. 

Comprehensive and Detailed Step-by-Step Explanation:The SPF = PASS result confirms the email came from an authorized server, but DKIM = FAIL indicates the message was not properly signed with the expected DomainKeys Identified Mail (DKIM) signature. DMARC = FAIL suggests that because DKIM failed, the overall email authentication failed. This scenario is consistent with a legitimate server sending an unsigned email.

In environments with fragile and legacy equipment, passive scanning is preferred to prevent any potential disruptions that active scanning might cause.

When assessing the security of an Operational Technology (OT) network, especially one with fragile and legacy equipment, it's crucial to use passive instead of active vulnerability scans. Active scanning can sometimes disrupt the operation of sensitive or older equipment. Passive scanning listens to network traffic without sending probing requests, thus minimizing the risk of disruption.