CompTIA CS0-003 Exam Dumps - Actual Questions Answers

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

The correct answer is B. Replace the current MD5 with SHA-256.

The vulnerability that the security analyst is able to exploit is a hash collision, which is a situation where two different files produce the same hash value. Hash collisions can allow an attacker to bypass the integrity or authentication checks that rely on hash values, and submit malicious files to the system. The web application uses MD5, which is a hashing algorithm that is known to be vulnerable to hash collisions. Therefore, the analyst should suggest replacing the current MD5 with SHA-256, which is a more secure and collision-resistant hashing algorithm.

The other options are not the best suggestions to mitigate the vulnerability with the fewest changes to the current script and infrastructure. Deploying a WAF (web application firewall) to the front of the application (A) may help protect the web application from some common attacks, but it may not prevent hash collisions or detect malicious files. Deploying an antivirus application on the hosting system © may help scan and remove malicious files from the system, but it may not prevent hash collisions or block malicious files from being submitted. Replacing the MD5 with digital signatures (D)may help verify the authenticity and integrity of the files, but it may require significant changes to the current script and infrastructure, as digital signatures involve public-key cryptography and certificate authorities.

Comprehensive and Detailed Explanation From Exact Extract:

The analyst should review PID 768 first because it is the parent process of another suspicious process (PID 1100) and it is also highly suspicious itself due to its unexpected file path.

Why PID 768 is the best first process to review

Path anomaly (strong IoC): Legitimate Windows binaries like calc.exe and cmd.exe are normally found in trusted OS directories (e.g., C:\Windows\System32\). In the table, both CALC.exe and CMD.exe appear in a user’s Documents folder (C:\Users\JDoe\Documents\...). That is a classic sign of masquerading (a malicious binary using a legitimate-sounding name). The All-in-One guide explicitly describes how attackers disguise malicious processes by using legitimate-sounding names and mimicking system processes.

Parent-child relationship (investigation priority): PID 1100 (Documents\CMD.exe) is suspicious, but it is a child of PID 768 (Documents\CALC.exe). Investigating the parent first helps you understand what spawned the suspicious child, what activity preceded it, and whether PID 768 is the root of the execution chain. The All-in-One guide highlights that analysts should examine process parent-child relationships and investigate unexpected dependencies as a way to detect malicious activity:Exact extract (All-in-One Exam Guide): “Analyze process dependencies Examine process parent-child relationships and investigate any unexpected or unusual dependencies that may indicate malicious activity.” It also emphasizes monitoring grandparent/parent/child relationships to detect deviations from normal process hierarchies:Exact extract (All-in-One Exam Guide): “Monitoring the relationships between processes, particularly grandparent, parent, and child relationships, can be a valuable method for detecting unusual activity.”

Abused/LOLBIN context: cmd.exe is a commonly abused Windows utility in attacks. The Sybex Study Guide notes that attackers often abuse built-in tools and that abnormal OS process behavior involving tools like cmd.exe can indicate compromise:Exact extract (Sybex Study Guide): “For Windows systems, a handful of built-in tools are most commonly associated with attacks like these, including cmd.exe…”

Why the other options are less correct

A (533) and B (740) are running from C:\Windows\System32\... which is the expected location for legitimate Windows binaries in normal circumstances, so they’re less suspicious than the copies running from a user Documents folder.

D (1100) is suspicious, but it is a child of PID 768. Investigating 768 first helps determine the origin and execution chain that led to the suspicious cmd instance.

References (CompTIA CySA+ CS0-003 documents / study guides used):

Mya Heath et al., CompTIA CySA+ All-in-One Exam Guide (CS0-003): parent/child process dependency analysis; process hierarchy monitoring; masquerading techniques

Mike Chapple & David Seidl, CompTIA CySA+ Study Guide (CS0-003): abnormal OS process behavior; cmd.exe commonly associated with attacks