An issue with the DAT 5958 update to the McAfee VirusScan Enterprise product causes PCs running Microsoft Windows XP Service Pack 3 to crash. The DAT 5958 update incorrectly identifies the system file svchost.exe as containing malicious code belonging to w32/wecorl.a. When the McAfee software tries to clean the mistakenly identified malicious code from the svchost.exe it causes the Denial of Service, Blue Screen of Death or DCOM error conditions rendering the affected PC unusable.
McAfee advise that the issue has been resolved in the 5959 DAT file release which is availble to download from the McAfee Security Update page at http://www.mcafee.com/apps/downloads/security_updates/dat.asp?region=us&segment=enterprise
McAfee also have a number of workarounds available at http://vil.nai.com/vil/5958_false.htm