hardMultiple ChoiceObjective-mapped
CV0-004 Practice Question: A company has deployed a multi-tier application…
A company has deployed a multi-tier application on a public cloud platform. The security team discovers that a Compute Instance is communicating with an external IP address known for malicious activity. The instance is part of an auto scaling group. What is the BEST immediate action to contain the threat while minimizing downtime?
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Remove the instance from the auto scaling group and attach a security group that blocks all traffic.
Isolating the compromised instance by detaching it from the auto scaling group and applying a security group that denies all traffic can quickly contain the threat. Network ACLs are attached to subnets and changing them could affect other instances. Suspending the auto scaling group alone may not stop the current instance. Updating routing tables is complex and could disrupt legitimate traffic.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Suspend the auto scaling group to prevent additional instances from being launched.
Why it's wrong here
Suspending the group does not stop the current instance from communicating; the malicious traffic continues.
- ✓
Remove the instance from the auto scaling group and attach a security group that blocks all traffic.
Why this is correct
This isolates the specific instance without affecting other instances, and blocking traffic stops the malicious communication.
- ✗
Use a routing table blackhole to drop traffic from the instance.
Why it's wrong here
Blackholing traffic via routing is complex and could be disruptive; also, routing tables affect all traffic in the VPC.
- ✗
Modify the network ACL for the subnet to deny traffic to the malicious IP.
Why it's wrong here
Network ACL changes affect all instances in the subnet, potentially causing collateral damage to other instances.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This CV0-004 practice question is part of Courseiva's free CompTIA 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 CV0-004 exam.