Reports indicate that new releases of a McAfee DAT file that was distributed to VirusScan applications has caused errors on certain Microsoft Windows XP-based systems.
As a result of installing the 5958 DAT file and rebooting, systems may be rendered unusable. Impacted systems may continuously reboot after reporting false virus infections related to the W32/Wecorl.a virus, which is described by McAfee in the following virus profile: W32/Wecorl.a. Because affected systems may only become unusable after a reboot, users are advised not to restart systems with the affected DAT file.
Administrators can remove the affected DAT file from systems by entering Microsoft Windows Safe Mode and restoring the DAT file to a previous version.
Alternately, administrators can prevent McAfee VirusScan from installing the affected updates by blocking internal clients and distribution servers from accessing McAfee update servers. Administrators are also advised to test updates before distributing them to client systems.
McAfee has released a knowledgebase article with various workarounds at the following link: KB68780