Ace Your CS0-003 CompTIA CySA+ Exam

The correct answer is A. MTTD — Mean Time to Detect — measures the average time between the beginning of a security incident and its detection. A shorter MTTD means the organization detects incidents faster, which can reduce attacker dwell time, limit damage, and reduce the incident’s overall impact.

Exact supporting extract: the Secbay CySA+ guide defines MTTD as the average duration between the occurrence of a security incident and its detection. It states that MTTD reflects the effectiveness of monitoring and detection capabilities and that reducing MTTD improves cybersecurity resilience.

The official CySA+ objectives include mean time to detect, mean time to respond, mean time to remediate, and alert volume under incident response metrics and KPIs.

Why the other options are incorrect:

B is incorrect because MTTD does not guarantee leadership is notified before exploitation.

C is incorrect because the time between detection and response is closer to MTTR, not MTTD.

D is incorrect because MTTD is a reporting metric, not a regulatory compliance process.

A is correct because faster detection normally reduces potential incident impact.

Comprehensive and Detailed Step-by-Step Explanation:A tabletop exercise is a structured simulation that allows teams to practice and evaluate their incident response procedures and coordination without actual operational impact. These exercises are used to identify gaps in processes and ensure preparedness for real-world threats.

Automatingthe generation of NIDS (Network Intrusion Detection System) rulesbased onStructured Threat Information eXpression (STIX) messagesis apractical use of automationin security operations​.

Option B (Privileged access requests)should involve human oversight due to thehigh risk of unauthorized access.

Option C (PKI identity verification)requires manualdocument verificationandhuman approval.

Option D (Malware analysis)often requiressandboxing and behavioral analysis, which benefit from human expertise.

Thus,A is the correct answer, asautomating threat intelligence ingestion and rule creation enhances efficiency in intrusion detection​.

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.