Zero-Trust Endpoint Isolation: Containment via Offline SIDs

Mon, 30 Mar 2026 16:20:00 -0700

When a user is terminated in Active Directory, the first line of defense is instantly engaged: denial of corporate access, which disconnects their VPN sessions and blocks interactive logins through the Domain Controller (DC).

However, there is a critical risk vector. If the employee (or a malicious attacker) has their corporate laptop, the local Windows Cached Credentials will continue to operate. This allows them to log into the machine “offline” (from the domain) and extract sensitive files locally onto a USB drive without needing to be connected to the corporate VPN or internal network.

Zero Trust on Mexicali IT

Zero-Trust Endpoint Isolation: Containment via Offline SIDs