CS0-003 Exam Dumps - CompTIA CySA+ Questions and Answers

Allowing anonymous read access to /etc/passwdis acriticalvulnerability because it canexpose user account details, aiding attackers inpassword cracking and privilege escalation​.

Option B (Anonymous FTP access)is a risk, but /etc/passwd exposure ismore criticalas it directly affects user authentication.

Option C (Defender updates disabled)isimportant, but it does not present animmediateattack vector like credential exposure.

Option D (less escape exploit)is significant, but it requires user interaction, making itless immediate than a global credential leak.

Thus,A is the correct answer, as it representsan immediate, high-impact security risk​.

A well-defined timeline of the events is the most important factor to ensure accurate incident response reporting, as it provides a clear and chronological account of what happened, when it happened, who was involved, and what actions were taken. A timeline helps to identify the root cause of the incident, the impact and scope of the damage, the effectiveness of the response, and the lessons learned for future improvement. A timeline also helps to communicate the incident to relevant stakeholders, such as management, legal, regulatory, or media entities. The other factors are also important for incident response reporting, but they are not as essential as a well-defined timeline. Official References:

https://www.ibm.com/topics/incident-response

https://www.crowdstrike.com/cybersecurity-101/incident-response/incident-response-steps/

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

A social engineering attack is a type of cyberattack that relies on manipulating human psychology rather than exploiting technical vulnerabilities. A social engineering attack may involve deceiving, persuading, or coercing users into performing actions that benefit the attacker, such as clicking on malicious links, divulging sensitive information, or granting access to restricted resources. An obfuscated link is a link that has been disguised or altered to hide its true destination or purpose. Obfuscated links are often used by attackers to trick users into visiting malicious websites or downloading malware. In this case, an incident response analyst notices multiple emails traversing the network that target only the administrators of the company. The email contains a concealed URL that leads to an unknown website in another country. This indicates that the analyst is witnessing a social engineering attack using obfuscated links.

The correct answer is A. Implanted a backdoor.

A backdoor is a method that allows an unauthorized user to access a system or network without the permission or knowledge of the owner. A backdoor can be installed by exploiting a software vulnerability, by using malware, or by physically modifying the hardware or firmware of the device. A backdoor can be used for various malicious purposes, such as stealing data, installing malware, executing commands, or taking control of the system.

In this case, the consultant implanted a backdoor in the website by using an HTML and PHP code snippet that displays an image of a shutdown button and an alert message that says “Exit”. However, the code also echoes the remote address of the server, which means that it sends the IP address of the visitor to the attacker. This way, the attacker can identify and target the visitors of the website and use their IP addresses to launch further attacks or gain access to their devices.

The code snippet is an example of a clickjacking attack, which is a type of interface-based attack that tricks a user into clicking on a hidden or disguised element on a webpage. However, clickjacking is not the main goal of the consultant, but rather a means to implant the backdoor. Therefore, option C is incorrect.

Option B is also incorrect because privilege escalation is an attack technique that allows an attacker to gain higher or more permissions than they are supposed to have on a system or network. Privilege escalation can be achieved by exploiting a software vulnerability, by using malware, or by abusing misconfigurations or weak access controls. However, there is no evidence that the consultant implemented privilege escalation on the website or gained any elevated privileges.

Option D is also incorrect because patching is a process of applying updates to software to fix errors, improve performance, or enhance security. Patching can prevent or mitigate various types of attacks, such as exploits, malware infections, or denial-of-service attacks. However, there is no indication that the consultant patched the web server or improved its security in any way.

Business process interruption is the inhibitor to remediation that this scenario illustrates. Business process interruption is when the remediation of a vulnerability or an incident requires the disruption or suspension of a critical or essential business process, such as the point-of-sale application. This can cause operational, financial, or reputational losses for the organization, and may outweigh the benefits of the remediation. Therefore, the organization may decide to postpone or avoid the remediation until a more convenient time, such as a change freeze window, which is a period of time when no changes are allowed to the IT environment12. Service-level agreement, degrading functionality, and proprietary system are other possible inhibitors to remediation, but they are not relevant to this scenario. Service-level agreement is when the remediation of a vulnerability or an incident violates or affects the contractual obligations or expectations of the service provider or the customer. Degrading functionality is when the remediation of a vulnerability or an incident reduces or impairs the performance or usability of a system or an application. Proprietary system is when the remediation of a vulnerability or an incident involves a system or an application that is owned or controlled by a third party, and the organization has limited or no access or authority to modify it3. References: Inhibitors to Remediation — SOC Ops Simplified, Remediation Inhibitors - CompTIA CySA+, Information security Vulnerability Management Report (Remediation…

The XML file containsJavaScript embedded within a <description> tagthat executes an alert message, which is a commonCross-Site Scripting (XSS)attack vector. The issue occurs becausethe XML schema does not restrict the input to safe characters, allowingarbitrary script executionwhen the XML file is processed by a vulnerable application.

Solution: Implement Input Validation Using an XML Schema Constraint

Option Benforces awhitelist approachby allowingonly alphanumeric characters and spaces([a-zA-Z 0-9]*).

This prevents the inclusion ofmalicious JavaScript or special characterssuch as <, >, or &, which are required for XSS injection​.

Why are the other options incorrect?

Option A: Restricts input to aSocial Security Number (SSN) format ([0-9]{3}-[0-9]{2}-[0-9]{4}). While it prevents JavaScript injection, it is too restrictive and would break legitimate text-based content in the XML.

Option C: Restricts input toonly numeric values ([0-9]*), preventing JavaScript injection but also breaking legitimate non-numeric content in the field.

Option D: Restricts input to asingle positive integer, which does not align with the expected text-based content.

Thus,Option Bis the correct answer, as it enforces proper input validation while still allowing expected text input​.

EDR stands for Endpoint Detection and Response, which is a tool that collects and aggregates data from various endpoints, such as laptops, servers, or mobile devices. EDR helps analysts monitor, detect, and respond to threats and incidents on the endpoints. EDR is more suitable than DLP (Data Loss Prevention), NAC (Network Access Control), or NIDS (Network Intrusion Detection System) for data collection and aggregation from endpoints.

From the logs, PC3 showsoutlook.exe spawning excel.exe at 1:15 PM, and laterexcel.exe spawning procdump.exe at 1:16 PM. This is highly suspicious becauseoutlook.exe should not normally launch Excel, andprocdump.exe is often used by attackers to dump process memory, which is a common technique in credential theft​.

PC1:Running expected Windows processes (wininit.exe spawning services.exe and lsass.exe).

PC2:Running a browser process (chrome.exe) from explorer.exe, which is normal.

PC3:Highly suspicious behavior (Excel spawning procdump.exe).

PC4:Running mstsc.exe (Remote Desktop) from explorer.exe, which is expected.

PC5:Running Firefox from explorer.exe, which is normal.

Thus,PC3 should be prioritized for investigationdue to its potential involvement in credential theft.

D ("grnail.com") is a suspicious domain that resembles "gmail.com."

The high "bytes out" value (525,984 bytes) indicates potential data exfiltration.

Attackers often use typosquatting (e.g., "grnail.com" instead of "gmail.com") to trick users into visiting malicious sites.

Why Not Other Options?

A (Netflix, B YouTube, C TikTok) → Large downloads, but expected behavior for streaming sites.

E (Google Translate) → Low data volume, no exfiltration risk.

F (Office.com) → Microsoft service, no indication of malicious activity.