AWS Forensics: Investigating an Infrastructure Breach

The Incident

Detecting Anomalous Activity in the Cloud

A mid-sized technology firm contacted Dravincon after detecting an unexpected 400% increase in their monthly AWS bill, combined with anomalous traffic spikes from their production VPC. Initial internal assessments were unable to pinpoint the source of the compromise or determine if customer data had been accessed.

Immediate Challenge

• Unknown entry point and persistence mechanism of the threat actor.
• Identifying the extent of unauthorized data access or exfiltration.
• Maintaining service availability while conducting forensics.
• Stopping the rapidly escalating operational costs.

Dravincon's Forensics Methodology

We deployed a rapid-response cloud forensics team to execute a four-phase investigation:

1. Evidence Collection & Preservation: Secured AWS CloudTrail logs, GuardDuty alerts, and VPC Flow Logs for immutable timeline analysis.
2. Threat Reconstruction: Identified a compromised IAM user with over-privileged permissions as the initial entry vector.
3. Persistence Analysis: Discovered a dormant backup access key and a rogue Lambda function used for egress traffic.
4. Containment & Eradication: Rotated all secrets, revoked rogue permissions, and evicted the threat actor within 24 hours.

Key Technologies Leveraged

AWS CloudTrail, Amazon GuardDuty, AWS Config, VPC Flow Logs, Custom Python Forensics Scripts.

Results & Business Value

• Threat Actor Evicted: Successful eradication of the actor and all persistence mechanisms.
• Data Integrity Verified: Forensics confirmed zero customer data exfiltration; the actor was primarily interested in compute resource hijacking.
• Cost Optimization: Hardened the environment and reduced monthly AWS spend by $1,200 through removal of rogue resources.
• Future Readiness: Implemented AWS Control Tower and SCPs (Service Control Policies) for automated guardrails.

Key Takeaway

Cloud incidents require specific forensics expertise beyond traditional network security. Visibility (logging) and Governance (IAM) are the two primary pillars of cloud resilience.