What action does Proofpoint Collab Protection take when a malicious URL is detected?

Proofpoint Collab Protection extends threat controls into collaboration channels (e.g., links shared in chat/collaboration platforms). When a malicious URL is detected, the immediate containment objective is to prevent a user from reaching the destination. The standard enforcement action is to redirect the user to a block page (D), analogous to URL Defense time-of-click blocking in email. This prevents credential harvesting and drive-by compromise while providing clear user feedback that the link was identified as unsafe. From an IR containment perspective, a block-page redirect also creates consistent telemetry: analysts can correlate attempted access events, identify which users attempted to follow the link, and scope the spread of the malicious content across channels (who posted it, who received it, who clicked). Unlike “deleting the URL from the system,” which is not realistic in distributed collaboration content, the block-page model is an enforceable control that works at access time. In recovery, responders still validate whether any users accessed the URL outside protected paths and then apply additional mitigations (IOC blocking, user notification, and account checks if the link was credential-phishing).