Investigation is the systematic examination of an event, claim, or suspected activity to establish what happened, when it happened, and who or what was involved. In information security, it commonly covers suspected intrusions, misuse of accounts, data exposure, fraud, and control failures. Investigators reconstruct an event from sources such as authentication records, endpoint artifacts, network telemetry, cloud logs, and disk or memory images, then determine the affected systems, data, and attack path.
Reliable investigations depend on preserving evidence without altering it, recording its provenance, and separating confirmed facts from assumptions. Findings can guide containment and recovery, reveal vulnerabilities that require remediation, and provide threat intelligence about tools or techniques used against an organization. Privacy and legal requirements may restrict what data can be collected or shared, while weak logging, short retention, or uncontrolled access can leave important questions unanswered and undermine any disciplinary, regulatory, or judicial action.