performing-cloud-forensics-with-aws-cloudtrail

Performing Cloud Forensics with AWS CloudTrail

When to Use

• When investigating suspected AWS account compromise
• After detecting unauthorized API calls or credential exposure
• During incident response involving cloud infrastructure
• When analyzing S3 data exfiltration or IAM privilege escalation
• For post-incident forensic timeline reconstruction

Prerequisites

• AWS account with CloudTrail enabled (management and data events)
• IAM permissions for cloudtrail:LookupEvents, s3:GetObject, athena:StartQueryExecution
• boto3 Python SDK installed
• CloudTrail logs delivered to S3 with optional Athena table configured
• AWS CLI configured with appropriate credentials

Workflow

1. Scope Investigation: Identify timeframe, affected accounts, and compromised credentials.
2. Query CloudTrail: Use boto3 lookup_events or Athena to retrieve relevant API events.
3. Filter by Indicators: Search for suspicious user agents, source IPs, and event names.
4. Reconstruct Timeline: Build chronological sequence of attacker actions from API calls.
5. Analyze Access Patterns: Identify data access, IAM changes, and resource modifications.
6. Identify Persistence: Check for new IAM users, access keys, roles, or Lambda functions.
7. Generate Report: Produce forensic timeline with findings and remediation steps.

Key Concepts

Concept	Description
LookupEvents	CloudTrail API to query management events (last 90 days)
Athena Queries	SQL queries against CloudTrail logs in S3 for historical analysis
User Agent Analysis	Identify tool signatures (AWS CLI, SDK, console, custom)
AccessKeyId	Track activity by specific IAM access key
EventName	AWS API action name (e.g., GetObject, CreateUser, AssumeRole)
sourceIPAddress	Origin IP of API call for geolocation analysis

Tools & Systems

Tool	Purpose
boto3 CloudTrail client	Programmatic CloudTrail event lookup
AWS Athena	SQL-based analysis of CloudTrail S3 logs
AWS CLI	Command-line CloudTrail queries
jq	JSON processing for CloudTrail event parsing
CloudTrail Lake	Advanced event data store with SQL query support

Output Format

Forensic Report: AWS-IR-[DATE]-[SEQ]
Account: [AWS Account ID]
Timeframe: [Start] to [End]
Compromised Credentials: [Access Key IDs]
Suspicious Events: [Count]
Source IPs: [List of attacker IPs]
Actions Taken: [API calls by attacker]
Data Accessed: [S3 objects, secrets, etc.]
Persistence Mechanisms: [New users, keys, roles]