- A
Modify the security group attached to the instance to deny all outbound traffic, and let Auto Scaling launch a replacement instance.
This immediately blocks outbound communication from the compromised instance while Auto Scaling replaces it, minimizing downtime.
- B
SSH into the instance and run a script to kill the mining process.
Why wrong: Assuming the instance is compromised, SSH access may be risky; the attacker could have rootkit. Also, this does not prevent the process from restarting.
- C
Detach the instance from the Auto Scaling group and isolate it by removing all security group rules.
Why wrong: Detaching does not block traffic; removing security group rules takes effect but may take time to propagate. Also, the instance remains running and could still cause harm.
- D
Immediately terminate the compromised EC2 instance and allow Auto Scaling to launch a new instance.
Why wrong: Termination removes the instance but does not immediately block outbound traffic; the instance may still have network connectivity briefly. Also, if the attacker has persistence, they might re-launch via other means.
SCS-C02 Threat Detection and Incident Response Practice Question
This SCS-C02 practice question tests your understanding of threat detection and incident response. 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.
A company runs a critical web application on a fleet of EC2 instances behind an Application Load Balancer (ALB). The application uses an Aurora MySQL database. The security team receives an alert from Amazon GuardDuty that a specific EC2 instance is exhibiting behavior consistent with a cryptocurrency mining attack, including outbound connections to known mining pools. The instance is part of an Auto Scaling group that uses a launch template with a security group that allows outbound HTTPS traffic to 0.0.0.0/0. The security engineer needs to contain the incident while minimizing downtime for the application. The engineer has already taken a forensic snapshot of the instance's EBS volume. Which course of action should the engineer take next?
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
Modify the security group attached to the instance to deny all outbound traffic, and let Auto Scaling launch a replacement instance.
Option A is correct because modifying the security group to deny all outbound traffic immediately stops the cryptocurrency mining communication to known mining pools without terminating the instance, preserving forensic data. The Auto Scaling group will detect the instance's health check failure (due to the application becoming unreachable) and automatically launch a replacement instance, minimizing downtime. This approach contains the incident while allowing the application to recover through the Auto Scaling group's self-healing mechanism.
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.
- ✓
Modify the security group attached to the instance to deny all outbound traffic, and let Auto Scaling launch a replacement instance.
Why this is correct
This immediately blocks outbound communication from the compromised instance while Auto Scaling replaces it, minimizing downtime.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
SSH into the instance and run a script to kill the mining process.
Why it's wrong here
Assuming the instance is compromised, SSH access may be risky; the attacker could have rootkit. Also, this does not prevent the process from restarting.
- ✗
Detach the instance from the Auto Scaling group and isolate it by removing all security group rules.
Why it's wrong here
Detaching does not block traffic; removing security group rules takes effect but may take time to propagate. Also, the instance remains running and could still cause harm.
- ✗
Immediately terminate the compromised EC2 instance and allow Auto Scaling to launch a new instance.
Why it's wrong here
Termination removes the instance but does not immediately block outbound traffic; the instance may still have network connectivity briefly. Also, if the attacker has persistence, they might re-launch via other means.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates may think immediate termination (Option D) is the fastest containment method, but they overlook that security group modification can contain the threat instantly without destroying evidence or causing unnecessary downtime.
Detailed technical explanation
How to think about this question
Security groups are stateful and act as a virtual firewall at the instance level; modifying the outbound rule to deny all traffic (0.0.0.0/0) blocks all egress, including HTTPS (TCP/443) to mining pools, without affecting inbound traffic. The Auto Scaling group's health check (default: EC2 status check) will fail when the application becomes unreachable due to blocked outbound traffic, triggering a replacement instance launch from the launch template. This containment method preserves the compromised instance for further forensic analysis (e.g., memory dump, disk analysis) while ensuring application continuity.
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 healthcare organisation deploys an application with a public-facing web tier and a private database tier. The database subnet has no public IP and only accepts connections from the web tier's security group. Questions like this test whether you can design cloud network isolation using VNets/VPCs, subnets, and security group rules.
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.
- →
Threat Detection and Incident Response — study guide chapter
Learn the concepts, then practise the questions
- →
Threat Detection and Incident Response practice questions
Targeted practice on this topic area only
- →
All SCS-C02 questions
1,738 questions across all exam domains
- →
AWS Certified Security Specialty SCS-C02 study guide
Full concept coverage aligned to exam objectives
- →
SCS-C02 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related SCS-C02 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Threat Detection and Incident Response practice questions
Practise SCS-C02 questions linked to Threat Detection and Incident Response.
Security Logging and Monitoring practice questions
Practise SCS-C02 questions linked to Security Logging and Monitoring.
Identity and Access Management practice questions
Practise SCS-C02 questions linked to Identity and Access Management.
Management and Security Governance practice questions
Practise SCS-C02 questions linked to Management and Security Governance.
Infrastructure Security practice questions
Practise SCS-C02 questions linked to Infrastructure Security.
Data Protection practice questions
Practise SCS-C02 questions linked to Data Protection.
SCS-C02 fundamentals practice questions
Practise SCS-C02 questions linked to SCS-C02 fundamentals.
SCS-C02 scenario practice questions
Practise SCS-C02 questions linked to SCS-C02 scenario.
SCS-C02 troubleshooting practice questions
Practise SCS-C02 questions linked to SCS-C02 troubleshooting.
Practice this exam
Start a free SCS-C02 practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this SCS-C02 question test?
Threat Detection and Incident Response — This question tests Threat Detection and Incident Response — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Modify the security group attached to the instance to deny all outbound traffic, and let Auto Scaling launch a replacement instance. — Option A is correct because modifying the security group to deny all outbound traffic immediately stops the cryptocurrency mining communication to known mining pools without terminating the instance, preserving forensic data. The Auto Scaling group will detect the instance's health check failure (due to the application becoming unreachable) and automatically launch a replacement instance, minimizing downtime. This approach contains the incident while allowing the application to recover through the Auto Scaling group's self-healing mechanism.
What should I do if I get this SCS-C02 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.
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 →
Last reviewed: Jun 11, 2026
This SCS-C02 practice question is part of Courseiva's free Amazon Web Services 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 SCS-C02 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.