Infected antivirus update breaks Windows PCs

A number of BitDefender users, whose 64-bit Windows systems stopped working or were unable to be rebooted after updating their security programs, vented their frustrations by flooding the antivirus vendor's forum pages over the weekend.

According to an IDG report, users on forum boards started signaling the problem on Saturday evening. The complainants said several Windows files, and the security vendor's own program files, were identified as "Trojan.FakeAlert.5" malware after they performed an update for their BitDefender antivirus programs.

In an email update Monday to ZDNet UK's sister site ZDNet Asia, Vitor Souza, BitDefender's global communications director, explained that "multiple" BitDefender and Windows files which comprise .exe, .dll and other binary files, were incorrectly detected as malware and "moved to quarantine".

For more on this story, see Bad security update brings down PCs worldwide on ZDNet Asia.