Lesson 9 of 10

Incident Response in the Cloud

When a cloud breach occurs, the response process is fundamentally different from on-premises incident response. Evidence is ephemeral, infrastructure can be destroyed in seconds, and the blast radius can span multiple accounts and regions. This lesson covers cloud-specific IR procedures, forensic evidence collection, and how to contain and eradicate a cloud compromise while preserving evidence for investigation.

Learning Objectives — Deep Dive

Each objective below is broken down into plain English so you know exactly what you are learning, why it matters, and what you will be able to do when you are done. Mark each one complete as you work through the lesson.

0/4

In plain English

In simple terms: Build a cloud incident response plan aligned with NIST SP 800-61. This means building enough understanding that you can apply this concept in a real scenario — not just answer a quiz question about it, but actually use it when it matters. Focus on the "why" behind the concept, not just the "what."

Why this matters

Cloud infrastructure now hosts the majority of the world's data and applications. Misconfigured cloud resources are responsible for some of the largest data breaches in history. Cloud security skills are among the most in-demand and highest-paying in the entire field.

Real-world analogy

Think of it like learning to drive. You do not need to understand how the engine works to drive safely, but knowing the basics helps you diagnose problems and avoid mistakes that could cause accidents. The same principle applies here — foundational knowledge prevents costly errors.

What you will be able to do

Apply this skill in a real lab environment, explain it clearly to a colleague or client, and use it as a building block for the more advanced techniques that come later in this course.

Beginner tip

Do not try to memorize everything at once. Read through the material once to get the big picture, then go back and work through the lab. The hands-on practice is what makes the concepts stick — passive reading alone will not get you there.

Incident Response in the Cloud · Objective 1 of 4

VIDEO

Loading video…

Detect the incident

Review GuardDuty findings for high-severity alerts indicating active compromise.

aws guardduty list-findings --detector-id $(aws guardduty list-detectors --query "DetectorIds[0]" --output text) --finding-criteria file://gd-filter.json

Contain compromised credentials

Immediately attach a DenyAll policy to the compromised IAM user to stop further damage.

aws iam put-user-policy --user-name compromised-user --policy-name EmergencyDeny --policy-document file://deny-all.json

Investigate with CloudTrail

Query CloudTrail for all API calls made by the compromised identity in the last 24 hours.

aws cloudtrail lookup-events --lookup-attributes AttributeKey=Username,AttributeValue=compromised-user --start-time $(date -d "24 hours ago" --iso-8601=seconds) --query "Events[*].[EventTime,EventName,SourceIPAddress]" --output table

Isolate a compromised EC2 instance

Replace the instance's security group with an isolation group that blocks all inbound and outbound traffic.

aws ec2 modify-instance-attribute --instance-id i-xxxxxxxx --groups sg-isolation-only

Previous: Compliance & Governance in the Cloud Next Lesson