CompTIA CS0-003 - CompTIA CyberSecurity Analyst CySA+ Certification Exam

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 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

Comprehensive Detailed Explanation:The most effective and economical way to ensure the security of an automated information system is to design it with security in mind from the outset. This is often referred to as "security by design." Here’s a breakdown of each option and why option A is correct:

A. Originally designed to provide necessary security

Explanation: Systems designed with security from the beginning integrate secure practices and considerations during the development process. This approach mitigates the need for costly and complex retroactive security implementations, which are common in systems where security was an afterthought.

Cost Efficiency: Security implementations at the design stage can be embedded into the system architecture, reducing the costs associated with later modifications.

Effectiveness: Security-by-design approaches often result in robust systems that are more resilient to vulnerabilities because they address security concerns at each development phase.

B. Subjected to intense security testing

While rigorous security testing (such as penetration testing and vulnerability assessments) is essential, it is reactive. Security testing is more effective when applied to systems already designed with foundational security principles, ensuring that tests identify potential flaws in an inherently secure system.

C. Customized to meet specific security threats

Customizing security to meet specific threats addresses unique risks, but such a targeted approach may miss new or emerging threats not initially considered. It also risks neglecting fundamental security practices that apply universally, leading to potential vulnerabilities.

D. Optimized prior to the addition of security

Optimizing a system before adding security features may enhance performance but does not guarantee security. Security cannot be effectively added onto a system as an afterthought without incurring additional costs or creating potential weaknesses.

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.

The user has become an insider threat by downloading software that contains malware onto a computer that eventually infects numerous other systems. An insider threat is a person or entity that has legitimate access to an organization’s systems, networks, or resources and uses that access to cause harm or damage to the organization. An insider threat can be intentional or unintentional, malicious or negligent, and can result from various actions or behaviors, such as downloading unauthorized software, violating security policies, stealing data, sabotaging systems, or collaborating with external attackers.

Outdated librariesin a legacy web applicationintroduce security vulnerabilities, as theylack modern patchesandcontain known exploits​.

Option A (Misconfigured WAF)can contribute to security issues but is notinherent to legacy applications.

Option B (Data integrity failure)is apotential impactbut not a direct cause of recurring incidents.

Option D (Insufficient logging)affects detection, but theroot causeisinsecure, outdated components.

Thus,C (Outdated libraries) is the correct answer, aslegacy applications frequently suffer from unpatched vulnerabilities​.

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.

The best practice that the company should follow with this proxy is to decommission the proxy. Decommissioning the proxy involves removing or disposing of the proxy from the rack and the network, as well as deleting or wiping any data or configuration on the proxy. Decommissioning the proxy can help eliminate the vulnerability on the proxy, as well as reduce the attack surface, complexity, or cost of maintaining the network. Decommissioning the proxy can also free up space or resources for other devices or systems that are in use or needed by the company.

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

The analyst used the command nmap -sV -T4 -F insecure.org to discover the application versions on the vulnerable website. The -sV option in Nmap is used to perform version detection, which identifies the versions of the services running on open ports. The -T4 option sets the timing template for faster execution, and -F scans only the most common ports.