McAfee update causes Windows XP crashes

McAfee's popular antivirus software broke down on Wednesday, causing Windows XP computers to have networking problems or repeatedly reboot.

By midday Wednesday, reports began to indicate just how widespread and damaging the McAfee update was.

The University of Michigan's medical school reported that 8000 of its 25,000 computers crashed. Police in Lexington resorted to hand-writing reports and turned off their patrol car terminals as a precaution. Some jails cancelled visitation.

Early reports attributed the widespread problems to a routine McAfee update that caused computers with Microsoft's Service Pack 3 installed to incorrectly identify a legitimate operating system component as containing a virus.

The update effectively confused the PC's immune system, causing it to attack legitimate operating system processes in the same way that some diseases can cause the human immune system to turn inward.

A McAfee representative confirmed the problem to ZDNet Australia sister site CNET, and said the buggy update code had been removed from the company's servers and that a fixed version would be made available shortly.

"McAfee is aware that a number of customers have incurred a false-positive error due to incorrect malware alerts on Wednesday, 21 April. The problem occurs with the 5958 virus definition file (DAT) that was released on 21 April at 6am PT," the company said in a statement.

A report at the Internet Storm Center said the McAfee update registered a false positive and flagged the Windows file svchost.exe as a virus.

The update did not seem to cripple computers running Windows Vista or Windows 7.

Compounding what seems to be a day of snafus for the company was that it initially directed affected users to download a file from its support site. But after tens of thousands of irate users flooded into the forums, the site abruptly went offline, and began to return an error message.

McAfee has posted a web page on a separate site with detailed instructions on how to fix XP computers that have been crashing because of Wednesday's update. It recommends manually downloading and installing an "EXTRA.DAT" file, and then restore files that have been incorrectly quarantined.

But that option requires at least a modest amount of technical ability, and as of 1pm PDT, the company had not offered a better way. "McAfee is continuing to work on an automated solution," the page said. (In the meantime, click here for our guide on how to fix it.)

Via CNET News.com