KB225571.exe file hides a remote administration tool. If loaded, it provides a remote attacker with an access to the compromised computer. The person using KB225571.exe may cause serious damage by installing other malwares and stealing information.KB225571.exe remote administration tool (RAT) is distributed via spam emails. The malicious message is masked to look like it was sent by Microsoft Corporation. The message invites installing KB225571.exe which supposedly is an important update.

Source: http://www.spywared.com/spyware-removal-instructions/2009/06/30/remove-kb225571exe-kb225571exe-removal.html