The Microsoft Windows Malicious Software Removal Tool helps remove specific, prevalent malicious software from computers that are running Windows Vista, Windows Server 2003, Windows XP, or Windows 2000. The Malicious Software Removal Tool is released on the second Tuesday of every month. Each release of the tool helps detect and remove current, prevalent malicious software. This malicious software includes viruses, worms, and Trojan horses. Microsoft uses several metrics to determine the prevalence of a malicious software family and the damage that can be associated with it.
Actual update includes: WinNT/Haxdoor v1.24, severity – moderate (the Win32/Haxdoor family of trojans are rootkit-capable backdoor trojans which gather and send private user data to remote attackers).