How to Investigate a Stealer Log: From Raw Data to Incident Response

*Executive Summary:* This report explains how information-stealing malware (infostealers) produce stealer logs containing credentials, session cookies, and system metadata, and provides a step-by-step framework for triage, credential/session analysis, mapping organizational exposure, correlating threat intelligence (malware family, C2, marketplaces/IABs), and executing identity-centric incident response actions such as credential resets, session invalidation, forensic preservation, and ongoing monitoring.