W32.Blaster.Worm is a worm that will exploit the DCOM RPC vulnerability using TCP port 135. It will attempt to download and run a file, msblast.exe.
Infection Length: 6,176 bytes
Systems Affected: Microsoft IIS, Windows 2000, Windows NT, Windows XP
Systems Not Affected: Linux, Macintosh, OS/2, UNIX
For those of you wondering what port 135 is there for, it is none other than the Windows Update Port! Hooray, thanks Microsoft... not only do you open doors, but backdoors as well. The Symantec website listed below has removal instructions for the worm if you are infected. Also be sure to check Windows Update and look under "Critical Updates & Service Packs", this is where the patch is located for this exploit.
Symantec Security Response
Microsoft Window's Update Webpage
(Ya, I know it was discussed in another topic, but it's best to have a topic to keep people informed easier...)