Download details: Windows Malicious Software Removal Tool: “This tool checks your computer for infection by specific, prevalent malicious software (including Blaster, Sasser, and Mydoom) and helps to remove the infection if it is found. Microsoft will release an updated version of this tool on the second Tuesday of each month.”
It looks like XP and 2003 can automatically get updates through Windows Update. I have some friends who need to run this one.