Security firm says Microsoft 365 Copilot's AI agent feature "Cowork" could leak files on its own

Security researchers say Microsoft 365 Copilot’s Cowork agent can be abused through indirect prompt injection.

A malicious skill file may cause the agent to pull preauthorized download links from SharePoint or OneDrive.

The data can then be sent out via Teams or Outlook-looking actions, potentially exposing sensitive files.

The case shows how trusted enterprise files can trigger cross-system actions without clear user approval.