Privileged material is confidential legal information that is protected from disclosure, most often because it falls under attorney-client privilege or work-product protections. It can include legal advice, case strategy, client communications, drafts, and related records that should not be exposed to unauthorized parties.
In cyber security, privileged material is especially sensitive because a leak can damage litigation, expose client identity or business details, and create regulatory or ethical problems. Ransomware operators and data extortion groups often claim to have stolen privileged files to increase pressure on a victim, even before the claims are verified. Defenders reduce this risk by limiting access with least privilege, separating legal repositories from general file shares, encrypting sensitive documents, logging access, and quickly validating whether protected files were actually accessed or exfiltrated during an incident.