McAfee false-positive glitch fells PCs worldwide

The Register - UK ^ | July 4, 2009 | Dan Goodin

[ConservativeMind]

IT admins across the globe are letting out a collective groan after servers and PCs running McAfee VirusScan were brought down when the anti-virus program attacked their core system files. In some cases, this caused the machines to display the dreaded blue screen of death.

Details are still coming in, but forums here and here show that it's affecting McAfee customers in Germany, Italy, and elsewhere. A UK-based Reg reader, who asked to remain anonymous because he was not authorized by his employer to speak to the press, said the glitch simultaneously leveled half of a customer's 140 machines after they updated to the latest virus signature file.

"Literally half of the machines were down with this McAfee anti-virus message IDing valid programs as having this trojan," the IT consultant said. "Literally half the office switched off their PCs and were just twiddling their thumbs."

When the consultant returned to his office he was relieved that his own laptop, which also uses VirusScan, was working normally. Then, suddenly, when it installed the latest McAfee DAT file, his computer was also smitten. The anti-virus program identified winvnc.exe and several other legitimate files as malware and attempted to quarantine them. With several core system files out of commission, the machine was rendered an expensive paperweight.

A McAfee representative in the US didn't immediately respond to phone calls seeking comment. Friday is a holiday for many US employees in observance of Saturday's Independence Day.

Based on anecdotes, the glitch appears to be caused when older VirusScan engines install DAT 5664, which McAfee seems to have pushed out in the past 24 hours. Affected systems then begin identifying a wide variety of legitimate - and frequently crucial - system files as malware. Files belonging to Microsoft Internet Explorer, drivers for Compaq computers, and even the McAfee-associated McScript.exe were being identified as a trojan called PWS!hv.aq, according to the posts and interviews.

We're still trying to determine how widespread this false-positive glitch is being felt and whether people have found any reliable fixes. If you have insight, please leave a comment below. ®

[ConservativeMind]

For those with McAfee, please prevent the latest DAT (antivirus definition update) from coming down to your computer. If you already have and McAfee is set to prompt you, please do not let it erase files flagged as having the "PWS!hv.aq" virus until later in the week when McAfee has fixed this.

[Terpfen]

Another reason not to use McAfee products. Norton isn’t much better.

[ConservativeMind]

A really good set of reviews of antivirus programs, updated often, is available here:

http://www.av-comparatives.org

I use the free Avira antivirus (www.free-av.com), myself. Additionally, I use the free Windows Defender real-time spyware scanner.

For on-demand scanning, I use the free Malwarebytes.org’s program and the free Spybot S&D. If you think you have something remaining on your system, download Spyware Doctor as part of the Google Pack (it's free). Spyware Doctor leaves a fair amount of baggage, but it gets whatever remains (you can always uninstall it or disable the loading of the program and services if you are technically-inclined).

I've never found anything with the free Ad-aware that the others haven't found.

[tallyhoe]

I use Avira!!!!

[swmobuffalo]

Insight: use AVAST

[Terpfen]

I use Eset Smart Security on my Vista PC. Well worth the price of subscription, even if I primarily use a Mac.

[bboop]

We use ESET too.