The correct first action is to verify the alert by checking logs and network traffic. This step is critical because alerts can be triggered by legitimate high-volume activity, such as a scheduled backup to a cloud service or a large software update over port 443, which is standard HTTPS traffic. Prematurely blocking the IP or isolating the host without validation risks disrupting business operations and destroying potential forensic evidence. On the Certified Information Security Manager CISM exam, this scenario tests your grasp of the incident response lifecycle, specifically the “detection and analysis” phase, where validation precedes containment. A common trap is jumping to containment or eradication, but the exam emphasizes that an unverified alert is just noise. Remember the mnemonic “VICE” for the first steps: Verify, Isolate, Contain, Eradicate—always start with Verify.
CISM Incident Management Practice Question
This CISM practice question tests your understanding of incident management. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
An analyst receives an alert indicating a potential data exfiltration. The alert shows a host IP address 10.10.50.200 sending large amounts of data to an external IP address 203.0.113.5 over port 443. What should the analyst do FIRST?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "first"
Why it matters: Order matters here. You are being tested on which action comes before the others — not which action is generally useful.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Verify the alert by checking logs and network traffic
Option C is correct because the first step in incident response is to validate the alert. The analyst must verify that the traffic is indeed anomalous and not legitimate (e.g., a large backup or software update) by examining logs and packet captures. Premature action without verification could disrupt business operations or destroy forensic evidence.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
Block the external IP address immediately
Why it's wrong here
Blocking prematurely may disrupt legitimate traffic without confirmation.
✗
Escalate to the incident response team
Why it's wrong here
Escalation is appropriate after initial triage and verification.
✓
Verify the alert by checking logs and network traffic
Why this is correct
Verification ensures the incident is real before further action.
Clue confirmation
The clue word "first" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
Isolate the host from the network
Why it's wrong here
Isolation is a containment step that should follow verification.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often jump to containment (isolate or block) without first verifying the alert, confusing the urgency of a potential exfiltration with the disciplined step of validation required by the NIST SP 800-61 incident response lifecycle.
Detailed technical explanation
How to think about this question
Port 443 is used for HTTPS, which is encrypted. The analyst should use a network monitoring tool (e.g., Wireshark or Zeek) to inspect TLS handshake metadata, certificate details, and data volume patterns. In a real-world scenario, an attacker might use HTTPS to blend exfiltration with legitimate traffic, so verifying the destination IP's reputation (e.g., via threat intelligence feeds) is critical before any containment action.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A practitioner preparing for the CISM exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Incident Management — This question tests Incident Management — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Verify the alert by checking logs and network traffic — Option C is correct because the first step in incident response is to validate the alert. The analyst must verify that the traffic is indeed anomalous and not legitimate (e.g., a large backup or software update) by examining logs and packet captures. Premature action without verification could disrupt business operations or destroy forensic evidence.
What should I do if I get this CISM question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "first". Order matters here. You are being tested on which action comes before the others — not which action is generally useful.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A security operations center analyst receives an alert from the SIEM indicating a possible data exfiltration. The analyst is unsure if it is a true positive. What is the MOST appropriate action?
medium
✓ A.Review additional logs to confirm
B.Escalate to the incident response manager
C.Immediately block the source IP
D.Quarantine the affected system
Why A: Before escalating or taking containment actions, the analyst should gather additional evidence to confirm the alert. Option D is correct.
Last reviewed: Jun 11, 2026
Question Discussion
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This CISM practice question is part of Courseiva's free ISACA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the CISM exam.
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