From the email that I received from eeye:-
A worm began spreading on the Internet early Monday morning that exploits a recent vulnerability in Microsoft Operating Systems. The worm, dubbed Blaster, takes advantage of a known vulnerability in Microsoft RPC DCOM that affects all current versions of Windows NT, Windows 2000, Windows XP, and Windows Server 2003.
The worm begins by targeting Microsoft systems that have not been properly patched for the known RPC DCOM vulnerability. Once the worm detects an unpatched system, it will attempt to download and run a file called msblast.exe. If successful in infecting a system, the worm will propagate itself, modify Windows registry settings, and initiate a SYN flood denial-of-service attack on windowsupdate.com.
The worm payload does not contain any additional malicious content; however, because of the nature of the worm and the speed at which it attempts to impact systems, it can potentially create a denial-of-service attack against windowsupdate.com.
For further information and a technical description of the Blaster worm please visit:
eeye. They also have a free tool you can download (reg required) to see which machines are vulnerable…but then again you should have done that a long time ago, especially with running Windows Update! Their full suite of programs will also tell you if you are unlucky to have it running around your network.