Pass the CompTIA CySA+ CS0-003 Questions and answers with ValidTests

Root Cause Analysis (RCA)is the best approach toidentify and resolve the underlying cause of recurring incidents. It involves a systematic investigation of logs, configurations, and operational data to pinpoint the reason behindpersistent security issues​.

Option A (Vulnerability assessment)helpsidentify security weaknessesbut does not focus onrecurring operational issues.

Option C (Recurrence reports)trackpatternsbut do notresolve the root cause.

Option D (Lessons learned)is valuable but is typicallya post-mortem discussion rather than an investigative method.

Thus,B is the correct answer, asroot cause analysis is the best approach for diagnosing recurring availability issues​.

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.

The output shows that the web application has a cross-origin resource sharing (CORS) header that allows any origin to access its resources. This is a security misconfiguration that could allow malicious websites to make requests to the web application on behalf of the user and access sensitive data or perform unauthorized actions. The tuning recommendation is to configure the Access-Control-Allow-Origin header to only allow authorized domains that need to access the web application’s resources. This would prevent unauthorized cross-origin requests and reduce the risk of cross-site request forgery (CSRF) attacks.

A Service-Level Agreement (SLA) is a document that establishes customer expectations regarding the performance and quality of services provided by the SOC (Security Operations Center). It defines thelevel of service expected, including aspects like response times, availability, and support after regular work hours. An SLA helps in setting clear expectations and improving customer satisfaction by outlining the standards and commitments of the service provider.

Thelessons learnedphase is a formal step in the incident response process where teamsreview what went wrong, what worked, and how to improvefuture responses. Management uses this toadjust policies, procedures, and controlsbased on real incident experiences.

Tabletop (A)is a simulated discussion, not post-incident.

Root cause analysis (C)finds technical origins but doesn’t focus on process improvement.

Forensics (D)supports investigation but not process revision.

????Reference:

CS0-003 Domain 3.0 – Post-Incident Activities

Chapple & Seidl – Study Guide, Chapter 11: Containment and Recovery

The best way to prevent network printers from printing pages during a vulnerability scan is to create a tailored scan for the printer subnet that excludes the ports and services that trigger the printing behavior. The other options are not effective for this purpose: performing non-credentialed scans may not reduce the impact on the printers; ignoring embedded web server ports may not cover all the possible ports that cause printing; increasing the threshold length of the scan timeout may not prevent the printing from occurring.

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.

Fuzzing is a testing technique where invalid or random data is inputted into a system to find vulnerabilities, crashes, or unexpected behaviors. It’s commonly used in software security to identify flaws that could lead to security breaches. According to CompTIA’s CySA+ curriculum, fuzzing is a dynamic testing method for exposing application weaknesses. Options like static testing (B) involve analyzing code without execution, while reverse engineering (A) and debugging (D) involve different methodologies for understanding or fixing code, not intentionally stressing it.

Automation is the best concept to describe the example, as it reflects the use of technology to perform tasks or processes without human intervention. Automation can help to improve efficiency, accuracy, consistency, and scalability of various operations, such as identity and access management (IAM). IAM is a security framework that enables organizations to manage the identities and access rights of users and devices across different systems and applications. IAM can help to ensure that only authorized users and devices can access the appropriate resources at the appropriate time and for the appropriate purpose. IAM can involve various tasks or processes, such as authentication, authorization, provisioning, deprovisioning, auditing, or reporting. Automation can help to simplify and streamline these tasks or processes by using software tools or scripts that can execute predefined actions or workflows based on certain triggers or conditions. For example, automation can help to create, update, or delete user accounts in bulk based on a file or a database, rather than manually entering or modifying each account individually. The example in the question shows that an API is used to insert bulk access requests from a file into an identity management system. An API (Application Programming Interface) is a set of rules or specifications that defines how different software components or systems can communicate and exchange data with each other. An API can help to enable automation by providing a standardized and consistent way to access and manipulate data or functionality of a software component or system. The example in the question shows that an API is used to automate the process of inserting bulk access requests from a file into an identity management system, rather than manually entering each request one by one. The other options are not correct, as they describe different concepts or techniques. Command and control is a term that refers to the ability of an attacker to remotely control a compromised system or device, such as using malware or backdoors. Command and control is not related to what is described in the example. Data enrichment is a term that refers to the process of enhancing or augmenting existing data with additional information from external sources, such as adding demographic or behavioral attributes to customer profiles. Data enrichment is not related to what is described in the example. Single sign-on is a term that refers to an authentication method thatallows users to access multiple systems or applications with one set of credentials, such as using a single username and password for different websites or services. Single sign-on is not related to what is described in the example.

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.

The signature of the malware is a unique identifier that can be used to compare it with known malware samples and their behaviors. Open-source threat intelligence sources provide information on various types of malware, their indicators of compromise, and their mitigation strategies. By cross-referencing the signature with these sources, the analyst can determine the type of malware and its telemetry. The other options are not relevant for this purpose: configuring the EDR to perform a full scan may not provide additional information on the malware type; transferring the malware to a sandbox environment may expose the analyst to further risks; logging in to the affected systems and running netstat may not reveal the malware activity.

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

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. Thecritical 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.

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

The 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