Blasting Blaster
In mid-July, Microsoft supplied patches for a vulnerability in the DCOM Remote Procedure Call module that could allow a worm to download and run any program. Microsoft Windows NT4, 2000, XP, and Windows Server 2003 were affected. This Monday, machines without the patch became fair game for the fast-spreading Blaster worm. Blaster is set to launch a Distributed Denial of Service (DDoS) attack on windowsupdate.microsoft.com this Saturday, August 16th. You don't want to be a part of that, so be sure you have the patch installed.

But what if your system is one of tens of thousands already compromised by Blaster? You may not be able to install the patch, or to do much of anything. On most machines Blaster triggers a Windows shut down sequence with a 60-second warning, leaving no time for downloading. Your first step is to abort the shutdown by entering the command "shutdown /a" (no quotes) in the Start menu's Run dialog. With the countdown halted, you can try the free removal tool from Symantec or do the job by hand.

http://www.microsoft.com/security/security_bulletins/ms03-026.asp

http://securityresponse.symantec.com/avcenter/venc/data/w32.blaster.worm.removal.tool.html

http://www.pcmag.com/article2/0,4149,1217751,00.asp