The following information can be used to reduce delays between the release of new FEP definition releases, and when the new definitions are available to WSUS/Configuration Manager.
Delta FEP Definitions
- Released daily (every 8 hours) via Windows Update and WSUS at:
- 3 AM (EST)
- 11 AM (EST)
- 7 PM (EST)
Rebased FEP Definitions
- Released once a month. (“Patch Tuesday”)
- Includes antivirus and antispyware definitions
- Accumulation of previous months base file and delta definitions that were released since the previous rebase.
The frequency at which the updates are available to target computers is dependent upon a couple of factors:
- The frequency at which WSUS synchronizes with Windows Update.
- The process used for approving the updated definitions for deployment.
Reference: KB977939 – Description of Forefront Endpoint Security Definition Updates