CloudTrail suspicious events to investigate:
- ConsoleLogin from unexpected geolocation or IP
- CreateAccessKey for existing IAM user (persistence)
- RunInstances for crypto-mining (large instance types)
- PutBucketPolicy making S3 bucket public
- AssumeRole to cross-account roles
- DeleteTrail or StopLogging (defense evasion)
- CreateUser or AttachUserPolicy (privilege escalation)
Azure Indicators:
Azure Activity Log events to investigate:
- Sign-in from anonymous IP or TOR exit node
- Service principal credential added
- Role assignment changes (Owner, Contributor added)
- VM created in unusual region
- Storage account access key regenerated
- Conditional Access policy modified or deleted
- MFA disabled for user account
GCP Indicators:
GCP Audit Log events to investigate:
- SetIamPolicy changes granting broad access
- CreateServiceAccountKey for existing SA
- InsertInstance in unexpected zone
- SetBucketIamPolicy with allUsers
- DeleteLog or UpdateSink (log tampering)
Step 2: Contain Cloud Identity Compromise
Cloud containment is primarily an identity operation:
AWS Containment:
# Disable compromised IAM access keys
aws iam update-access-key --user-name compromised-user \
--access-key-id AKIA... --status Inactive
# Attach deny-all policy to compromised user
aws iam attach-user-policy --user-name compromised-user \
--policy-arn arn:aws:iam::aws:policy/AWSDenyAll
# Revoke all active sessions for compromised IAM role
aws iam put-role-policy --role-name compromised-role \
--policy-name RevokeOlderSessions --policy-document '{
"Version":"2012-10-17",
"Statement":[{
"Effect":"Deny",
"Action":"*",
"Resource":"*",
"Condition":{"DateLessThan":
{"aws:TokenIssueTime":"2025-11-15T15:00:00Z"}}
}]
}'
# Isolate compromised EC2 instance
aws ec2 modify-instance-attribute --instance-id i-0abc123 \
--groups sg-isolate-forensic
Steampipe: Open-source SQL-based tool for querying cloud APIs to investigate IAM configurations and resource states
Cartography (Lyft): Open-source tool for mapping cloud infrastructure relationships and identifying attack paths
Common Scenarios
Scenario: AWS Access Key Compromised via Public GitHub Repository
Context: AWS GuardDuty alerts on API calls from an unexpected IP address using an IAM user's access key. The key was accidentally committed to a public GitHub repository 4 hours ago.
Approach:
Immediately disable the compromised access key via AWS IAM
Attach AWSDenyAll policy to the affected IAM user
Query CloudTrail for all API calls made with the compromised key since exposure
Identify resources created or modified by the attacker (EC2 instances for crypto-mining, new IAM users for persistence)
Terminate unauthorized resources and remove backdoor IAM entities
Rotate all credentials the compromised user had access to
Enable GitHub secret scanning to prevent future credential leaks
Pitfalls:
Only disabling the access key without checking for new access keys or IAM users created as persistence
Not checking all AWS regions for attacker-created resources (crypto-miners deployed in every region)
Forgetting to revoke temporary credentials from assumed roles (STS tokens remain valid until expiry)
Not calculating the financial impact of unauthorized resource usage for insurance claims
Output Format
CLOUD INCIDENT RESPONSE REPORT
================================
Incident: INC-2025-1705
Cloud Provider: AWS (Account: 123456789012)
Date Detected: 2025-11-15T14:00:00Z
Detection Source: GuardDuty - UnauthorizedAccess:IAMUser/InstanceCredentialExfiltration
COMPROMISE SUMMARY
Initial Access: IAM access key exposed in public GitHub repo
Affected Identity: iam-user: deploy-bot (AKIA...)
Attacker IP: 203.0.113.42 (VPN exit node, Netherlands)
Duration: 4 hours (10:00 UTC - 14:00 UTC)
ATTACKER ACTIVITY (from CloudTrail)
10:15 UTC - DescribeInstances (reconnaissance)
10:18 UTC - RunInstances x 12 (c5.4xlarge, all regions - crypto-mining)
10:22 UTC - CreateUser "backup-admin" (persistence)
10:23 UTC - CreateAccessKey for "backup-admin"
10:25 UTC - AttachUserPolicy - AdministratorAccess to "backup-admin"
10:30 UTC - PutBucketPolicy - s3://data-bucket made public (exfiltration)
CONTAINMENT ACTIONS
[x] Original access key disabled
[x] User policy set to AWSDenyAll
[x] Backdoor IAM user "backup-admin" deleted
[x] 12 crypto-mining instances terminated (all regions)
[x] S3 bucket policy restored to private
FINANCIAL IMPACT
Unauthorized EC2: $2,847 (4 hours x 12 x c5.4xlarge)
Data Transfer: $127 (S3 public access data egress)
Total: $2,974
POST-INCIDENT HARDENING
1. GitHub secret scanning enabled
2. Access key rotation policy implemented
3. SCP preventing CloudTrail disablement deployed
4. GuardDuty auto-remediation Lambda configured
