Cloud Forensics
Cloud forensics collects and studies digital evidence after a security incident. Investigators work out what happened, how the attacker entered, which data the attacker touched, and how to prevent a repeat. Cloud environments change the rules because servers appear and vanish within minutes, and evidence can disappear with them.
The Crime Scene Analogy
Detectives tape off a crime scene, photograph everything, and gather evidence with gloves and labels. A careless step can destroy a fingerprint. Digital investigators follow the same discipline. They preserve evidence, study copies, and record each step.
Why the Cloud Makes Forensics Different
- Resources are temporary, so a container may vanish before anyone examines it
- Providers control the physical hardware, so investigators cannot pull a hard drive
- Data spreads across regions and legal systems
- Many customers share infrastructure, which limits what the provider can reveal
- Logs depend on settings the customer chose earlier
The Forensic Process
1. Identify --> 2. Preserve --> 3. Collect --> 4. Analyze --> 5. Report
What happened? Freeze changes Copy evidence Build timeline Findings +
safely fixes
Identify
Determine which systems, accounts, and data the incident affects.
Preserve
Isolate affected resources without deleting them. Snapshot disks, save memory when possible, and restrict access to the evidence.
Collect
Gather logs, snapshots, configuration records, and network captures. Record who collected each item and when.
Analyze
Build a timeline of attacker actions. Match log entries, file changes, and network activity to find the entry point and the reach of the attack.
Report
Document findings in plain language, list affected data, and recommend fixes.
Evidence Sources in the Cloud
| Source | What It Reveals |
|---|---|
| Audit logs | Who changed settings and created resources |
| Sign-in logs | Login times, locations, and methods |
| Network flow logs | Connections between systems |
| Disk snapshots | Files and programs on a virtual machine |
| Storage access logs | Which objects someone viewed or downloaded |
| Container and function logs | Activity inside short-lived workloads |
Chain of Custody
Chain of custody records who handled evidence, when, and why. A clean record proves that nobody tampered with the data. Courts and regulators demand it. Store evidence in a locked, access-limited account, and calculate file fingerprints at collection time to prove later that nothing changed.
Real-World Example: A Stolen Access Key
A company discovers unfamiliar virtual machines mining digital currency in its account. The security team snapshots the machines before shutting them down. Audit logs show that an access key, posted accidentally in a public code repository, created the machines at 2 a.m. Storage logs confirm that the attacker never read customer data. The team deletes the key, rotates related secrets, and adds scanning to catch keys in code.
Key in public repo --> Attacker uses key --> Creates 12 machines --> Logs capture activity
|
Investigator timeline <--------+
Preparing Before an Incident
- Turn on audit, sign-in, and network logging in every account.
- Send logs to a protected, separate account.
- Set retention periods that match legal needs.
- Prepare a playbook for snapshotting resources.
- Agree on contact paths with the cloud provider.
- Practice with a tabletop exercise.
Legal and Privacy Care
Investigators handle personal data, so access stays limited to people who need it. Local laws control where evidence travels and how long teams keep it. Involve legal counsel early.
Key Takeaways
Cloud forensics preserves and studies evidence from fast-changing environments. Preparation, logging, and careful documentation decide whether an investigation succeeds.