It would seem today’s botched definition update sent out to corporate users of McAfee’s anti-virus software has caused Windows XP workstations to fail with DCOM errors which then causes a reboot to occur; finally, upon start up loose network connectivity. This will turn into an absolute nightmare for I.T administrators because in most cases this may mean a fix will need to be applied manually by visiting each workstation directly. For some large corporate’s the ramifications to this will be massive if they have 10,000 systems spread globally!
Apparently this all came about because the definition update struck a false positive which lead to the engine deleting a svchost.exe from the Windows directory exclaiming it was infected.
Engadget has been following the story for most of the day: http://www.engadget.com/2010/04/21/mcafee-update–shutting-down-xp-machines/
It seems that McAfee have since posted an updated version of the definition package, as well as a Fix Tool for affected customers, although it also seems the Fix Tool will need to be executed on each effected machine which might cause a problem if the I.T team can’t connect to it over the network.. Check the McAfee support site for more information and regular updates on the issue, the link about has links to McAfee also.