The answer is blocking known malicious domains and IPs at the firewall and isolating infected workstations from the network. These two actions are appropriate during the containment phase because they directly stop the malware from communicating with command-and-control servers and prevent lateral spread to other workstations, which is the primary goal of containment—limiting damage without destroying evidence. On the CISM exam, this question tests your understanding of the incident response lifecycle, specifically the containment step, where speed and precision matter more than eradication or recovery. A common trap is confusing containment with eradication actions like running antivirus scans or patching vulnerabilities, which come later. Remember the mnemonic “C.I.T.” for Containment: Cut connectivity, Isolate hosts, and block Traffic at the perimeter—this will help you pick the two network-focused actions over system-level fixes.
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.
Which TWO actions are appropriate during the containment phase of an incident involving a malware outbreak on multiple workstations?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Isolate infected workstations from the network
Option C is correct because isolating infected workstations from the network is a primary containment action that prevents the malware from spreading laterally to other systems, limiting the scope of the incident. This is typically achieved by disconnecting network cables, disabling switch ports, or using network access control (NAC) to quarantine the affected hosts, which stops further propagation without destroying 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.
✗
Contact all users to warn them about the malware
Why it's wrong here
May cause unnecessary alarm and is not containment.
✗
Reimage all affected workstations immediately
Why it's wrong here
Reimaging is remediation, done after containment.
✓
Isolate infected workstations from the network
Why this is correct
Isolation stops lateral movement.
Related concept
Read the scenario before looking for a memorised answer.
✗
Notify customers about potential data breach
Why it's wrong here
Notification is external communication, not containment.
✓
Block known malicious domains and IPs at the firewall
Why this is correct
Blocks command-and-control communication.
Related concept
Read the scenario before looking for a memorised answer.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often confuse containment with eradication or communication, mistakenly selecting 'reimage all affected workstations immediately' as a containment step, when in fact reimaging is an eradication action that should occur after containment and evidence collection.
Detailed technical explanation
How to think about this question
Containment in incident management aims to stop the incident from causing further damage while preserving evidence for analysis. For a malware outbreak, isolating workstations at Layer 2 (e.g., disabling switch ports via SNMP or 802.1X) or Layer 3 (e.g., applying ACLs on the firewall) is more effective than user warnings because it immediately cuts off command-and-control (C2) channels and lateral movement vectors. Blocking known malicious domains and IPs at the firewall (Option E) is also a containment action because it prevents infected hosts from communicating with external C2 servers, which can stop data exfiltration and further payload downloads.
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: Isolate infected workstations from the network — Option C is correct because isolating infected workstations from the network is a primary containment action that prevents the malware from spreading laterally to other systems, limiting the scope of the incident. This is typically achieved by disconnecting network cables, disabling switch ports, or using network access control (NAC) to quarantine the affected hosts, which stops further propagation without destroying 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.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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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.
Question Discussion
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