CompTIA Updated CS0-003 Exam Questions and Answers by klara

Compensating controls are the best approach to minimize the risk of the outdated servers being compromised, as they can provide an alternative or additional layer of security when the primary control is not feasible or effective.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 Therefore, the security analyst should also consider upgrading or replacing the outdated servers as soon as possible.

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 securityfeatures. 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 correct answer is D because the analyst should first validate whether the suspicious DNS domains are malicious or legitimate. Random-looking DNS domains may indicate malware using a domain generation algorithm (DGA) for command-and-control, but they can also appear in legitimate services such as content delivery networks or software update mechanisms. Therefore, the best first step is to enrich the DNS indicators using threat intelligence and reputation sources.

Exact supporting extract: the CySA+ All-in-One guide explains that DNS tunneling and abnormal DNS queries may be used for command-and-control or exfiltration. It also states that high-entropy domains appear random or “gibberish” to humans and that malware may use DGAs for C2 communication. However, it also warns that computer-generated domain names can have legitimate uses in content delivery networks.

The same guide explains that threat research should help answer questions such as whether an artifact is benign, whether anyone has seen it before, and why it is present in the system. It further explains that reputation data for domains, URLs, and IP addresses helps determine whether activity is associated with malware, phishing, C2, or data exfiltration.

Why the other options are incorrect:

A is incorrect because allowing the domains without validation could permit C2 or data exfiltration.

B is incorrect because reinstalling the software does not determine whether the DNS activity is malicious.

C is incorrect because blocking all outbound connections is a containment action, not the best first investigative step when the analyst is still determining whether compromise occurred.

D is correct because threat intelligence/reputation lookup is the most appropriate first validation step for suspicious DNS indicators.

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