Ensure that a computer running Microsoft Forefront Threat Management Gateway is stored in a physically secure location. Physical access to a server is a high security risk. Physical access to a server by an unauthorized user could result in unauthorized access or modification, as well as installation of hardware or software designed to circumvent security. To maintain a secure environment, you must restrict physical access to the Forefront TMG computer.
If you suspect that the Forefront TMG computer was compromised, reinstall Forefront TMG.