Performing Cloud Incident Containment Procedures

Overview

Cloud incident containment requires cloud-native approaches that differ significantly from traditional on-premises response. Containment procedures must leverage platform-specific controls including security groups, IAM policies, network ACLs, and service-level isolation to restrict compromised resources while preserving forensic evidence. According to the 2025 Unit 42 Global Incident Response Report, responding to cloud incidents requires understanding shared responsibility models, ephemeral infrastructure, and API-driven operations. Effective containment involves credential revocation, resource isolation, evidence snapshot creation, and automated response playbook execution.

When to Use

• When conducting security assessments that involve performing cloud incident containment procedures
• When following incident response procedures for related security events
• When performing scheduled security testing or auditing activities
• When validating security controls through hands-on testing

Prerequisites

• Familiarity with incident response concepts and tools
• Access to a test or lab environment for safe execution
• Python 3.8+ with required dependencies installed
• Appropriate authorization for any testing activities

AWS Containment Procedures

1. Credential Compromise Containment

# Disable compromised IAM user access keys
aws iam update-access-key --user-name compromised-user \
  --access-key-id AKIA... --status Inactive

# List and disable all access keys for user
aws iam list-access-keys --user-name compromised-user
aws iam delete-access-key --user-name compromised-user --access-key-id AKIA...

# Attach deny-all policy to compromised user
aws iam put-user-policy --user-name compromised-user \
  --policy-name DenyAll \
  --policy-document '{
    "Version": "2012-10-17",
    "Statement": [{
      "Effect": "Deny",
      "Action": "*",
      "Resource": "*"
    }]
  }'

# Revoke all active sessions for IAM role
aws iam put-role-policy --role-name compromised-role \
  --policy-name RevokeOldSessions \
  --policy-document '{
    "Version": "2012-10-17",
    "Statement": [{
      "Effect": "Deny",
      "Action": "*",
      "Resource": "*",
      "Condition": {
        "DateLessThan": {"aws:TokenIssueTime": "'$(date -u +%Y-%m-%dT%H:%M:%SZ)'"}
      }
    }]
  }'

# Invalidate temporary credentials by updating role trust policy
aws iam update-assume-role-policy --role-name compromised-role \
  --policy-document '{"Version":"2012-10-17","Statement":[]}'

2. EC2 Instance Isolation

# Create quarantine security group (no inbound, no outbound)
aws ec2 create-security-group --group-name quarantine-sg \
  --description "Quarantine - No traffic allowed" --vpc-id vpc-xxxxx

# Remove all rules from quarantine SG (default allows outbound)
aws ec2 revoke-security-group-egress --group-id sg-quarantine \
  --ip-permissions '[{"IpProtocol":"-1","FromPort":-1,"ToPort":-1,"IpRanges":[{"CidrIp":"0.0.0.0/0"}]}]'

# Take forensic snapshot BEFORE containment
aws ec2 create-snapshot --volume-id vol-xxxxx \
  --description "Forensic snapshot - IR Case 2025-001" \
  --tag-specifications 'ResourceType=snapshot,Tags=[{Key=IR-Case,Value=2025-001}]'

# Apply quarantine security group to compromised instance
aws ec2 modify-instance-attribute --instance-id i-xxxxx \
  --groups sg-quarantine

# Tag instance as compromised
aws ec2 create-tags --resources i-xxxxx \
  --tags Key=IR-Status,Value=Contained Key=IR-Case,Value=2025-001

# Capture memory (if SSM agent available)
aws ssm send-command --instance-ids i-xxxxx \
  --document-name "AWS-RunShellScript" \
  --parameters 'commands=["dd if=/dev/mem of=/tmp/memory.dump bs=1M"]'

3. S3 Bucket Containment

# Block all public access
aws s3api put-public-access-block --bucket compromised-bucket \
  --public-access-block-configuration \
  BlockPublicAcls=true,IgnorePublicAcls=true,BlockPublicPolicy=true,RestrictPublicBuckets=true

# Apply deny policy to bucket
aws s3api put-bucket-policy --bucket compromised-bucket \
  --policy '{
    "Version": "2012-10-17",
    "Statement": [{
      "Sid": "DenyAllExceptForensics",
      "Effect": "Deny",
      "NotPrincipal": {"AWS": "arn:aws:iam::ACCOUNT:role/IR-Forensics"},
      "Action": "s3:*",
      "Resource": ["arn:aws:s3:::compromised-bucket","arn:aws:s3:::compromised-bucket/*"]
    }]
  }'

# Enable versioning to preserve evidence

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