In a recent update, Microsoft has included a patch to include a heuristic-based scan of all storage media which looks for "terrorism-related" material. If it finds anything it will then flag it and send it to an unidentifiable address.
The update will scan for any anti-activation exploits. It will then remain in the background even after the computer has been verified, waiting until the computer is either idle or "locked" by the user.
Even though this update isn´t required and is unselected when shown in the updates list, many users will assume it to be a bug fix update and include it.