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

Developing an organization ' s communication plans is crucial to ensure that incidents, especially those involving sensitive data like PH (Protected Health) data, are promptly reported to the relevant regulatory agencies. This is essential for compliance with legal and regulatory requirements, which often mandate timely notification of data breaches. Effective communication plans help the organization manage the breach response process, mitigate potential legal penalties, and maintain transparency with regulatory bodies.

A risk score is a numerical value that represents the potential impact and likelihood of a vulnerability being exploited. It can help to identify the potential loss incurred by an issue and prioritize remediation efforts accordingly. https://www.comptia.org/training/books/cysa-cs0-003-study-guide

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.

Implementing segmentation with ACLs is the best solution to secure the network. Segmentation is the process of dividing a network into smaller subnetworks, or segments, based on criteria such as function, location, or security level. Segmentation can help improve the network performance, scalability, and manageability, as well as enhance the network security by isolating the sensitive or critical data and systems from the rest of the network. ACLs are Access Control Lists, which are rules or policies that specify which users, devices, or applications can access a network segment or resource, and which actions they can perform. ACLs can help enforce the principle of least privilege, and prevent unauthorized or malicious access to the network segments or resources12. Configuring logging and monitoring to the SIEM, deploying MFA to cloud storage locations, and rolling out an IDS are all good security practices, but they are not the best solution to secure the network. Logging and monitoring tothe SIEM can help detect and analyze the network events and incidents, but they do not prevent them. MFA can help authenticate the users who access the cloud storage locations, but it does not protect the network from attacks or breaches. IDS can help identify and alert the network intrusions, but it does not block them34 . References: Network Segmentation: What It Is and How to Do It Right, What is an Access Control List (ACL)? | IBM, What is SIEM? | Microsoft Security, What is Multifactor Authentication (MFA)? | Duo Security, [What is an Intrusion Detection System (IDS)? | IBM]

Answer below images

Wiresharkis apacket capture and analysis toolthat allows analysts to inspect network traffic and detectcleartext credentialssent over protocols like HTTP, FTP, and Telnet​.

Option A (OpenVAS)is avulnerability scanner, not a network analysis tool.

Option B (Angry IP Scanner)identifiesactive hosts, but does not analyze packet contents.

Option D (Maltego)is used forOSINT and network reconnaissance, not packet inspection.

Thus,C (Wireshark) is the correct answer, as itcaptures and analyzes network packets to identify unencrypted passwords​.

To decide what to address first, CySA+ expects a risk-based prioritization approach, combining factors like:

Asset criticality/value (business impact)

Exposure/architecture (internet-facing vs. isolated/internal)

Patch availability / ability to remediate quickly

Exploitability / likelihood of exploitation

1) Server5 (Critical + Patch Yes) — prioritize immediately

Server5 sits in the database network, is marked Critical, and a patch is available. That combination makes it one of the highest priorities because you can rapidly reduce risk on an asset with the greatest business impact.

Secbay explicitly states that prioritization should align to asset criticality and business impact, and also notes that patch availability accelerates remediation:Exact extract (Secbay Press): “Prioritize vulnerabilities based on their severity, exploitability, and potential impact… Asset Criticality: Identify and prioritize vulnerabilities based on the criticality of the assets they affect…” and “Patch Availability… Action: Prioritize vulnerabilities for which patches are readily available, as prompt remediation is possible.”

The All-in-One guide emphasizes asset value/criticality as a major driver of how fast you remediate:Exact extract (All-in-One Exam Guide): “Asset value is likely one of the most important factors in determining how quickly you should remediate vulnerabilities…”

2) Server3 (Perimeter + High) — address immediately (mitigate now, patch later)

Server3 is in the perimeter network and rated High, making it more exposed to attack paths than internal-only systems. Even though no patch is available, the analyst must still “address” it first via mitigation/compensating controls (segmentation, firewalling, disabling vulnerable services, WAF where relevant, tighter ACLs, etc.) because perimeter exposure increases likelihood of exploitation.

The All-in-One guide makes the architecture/exposure point very directly:Exact extract (All-in-One Exam Guide – Exam Tip): “The architecture of your infrastructure should be a factor… Internet-facing hosts with sensitive information will likely be your highest priority, while isolated systems… may be able to wait a bit longer for remediation.”

Secbay’s prioritization guidance also highlights focusing on critical/high impact risks first and using risk-based prioritization.

Why not the others (briefly):

Server4 (Internal, High, Patch Yes): This is a strong candidate, but when choosing only two, perimeter high exposure (Server3) plus critical database with patch (Server5) generally outranks an internal high system.

Server2 (Perimeter, Low, Patch Yes): Exposed, but Low criticality.

Server1 / Server6 (Medium, No patch): Lower criticality and no patch—typically handled after higher-risk items, or mitigated as feasible.

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

Mya Heath et al., CompTIA CySA+ All-in-One Exam Guide (CS0-003): infrastructure architecture affects remediation priority; internet-facing hosts are typically highest priority; asset value drives remediation urgency

Secbay Press, CompTIA CySA+ Exam Prep Guide (CS0-003): vulnerability prioritization factors include asset criticality and patch availability; prioritize items with readily available patches for prompt remediation

Agent-based vulnerability scanning is a method that involves installing software agents on the target systems or networks that can perform local scans and report the results to a central server or console. Agent-based vulnerability scanning can reduce network traffic, as the scans are performed locally and only the results are transmitted over the network. Agent-based vulnerability scanning can also provide more accurate and up-to-date results, as the agents can scan continuously or on-demand, regardless of the system or network status or location.

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

XDR logs will confirm the malware infection because XDR is a system that collects and analyzes data from multiple sources, such as endpoints, networks, cloud applications, and email security, to detect and respond to advanced threats12. XDR can provide a comprehensive view of the attack chain and the context of the malware infection. Firewall logs, IDS logs, and MFA logs are not sufficient to confirm the malware infection, as they only provide partial or indirect information about the network traffic, intrusion attempts, or user authentication. References: Cybersecurity Analyst+ - CompTIA, XDR: definition and benefits for MSPs| WatchGuard Blog, Extended detection and response - Wikipedia