Symptoms
The Microsoft Forefront Threat Management Gateway 2010 Firewall Service process may leak memory over time if the Malware Inspection feature is enabled.
Note You may be able to verify this problem by monitoring the Performance Monitor counters for the WSPSRV.EXE process. In this way, you can determine whether the Private Bytes, Virtual Bytes and Working Set processes continually increase without ever decreasing.Resolution
To resolve this problem, install Rollup 4 for Forefront Threat Management Gateway (TMG) 2010 Service Pack 2.
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
References
Learn about the terminology Microsoft uses to describe software updates.