Topic: False positive detection by F-Secure Mac scanner (JS/Brooks.gen!A, prefs.js ...)

[Samker]

F-Secure has apologised about a bug in its consumer-focused Mac security software that left surfers fighting against their own browsers as clean files were wrongly classified as malign: http://www.f-secure.com/weblog/archives/00002121.html

A faulty definition in the beta version of F-Secure Mac Protection meant that the software had been wrongly identifying some benign files as being contaminated with malware. As a result some clean files were consigned to the trash bin.

The Finnish security firm responded promptly within hours of the discovery of the problem on Monday by withdrawing the mis-firing definition update and publishing a revised list. It also released a tool that restored files back to their original locations.

Users would not have been too badly inconvenienced providing they avoided emptying their trash during the period when the incorrect updates were applied. Discussion on F-Secure's support forum suggested the problem manifested itself as a battle between users' miscuing security software and their browsers that resulted in browser crashes and more multiple alerts as benign script and download elements were binned: http://forum.f-secure.com/topic.asp?TOPIC_ID=16423

F-Secure has apologised for the problem, which only affected users of its Mac security software. Windows- and Linux-based users of anti-virus packages from F-Secure were unaffected by the problem.

Such false alert problems are all too common to Windows users. Difficulties in these cases hit hardest in cases where security software classifies system files as malign. Stripped of these vital files, systems become unstable.

Vendors try hard to screen against the release of problematic updates but the huge volume of Windows malware spewed out every day makes this process increasingly difficult. Even though similar strains of malware can be pegged with generic detection signatures, updates are still a big part of the mix and a huge ramp-up in Trojan creation inevitably means more frequent updates.

Developers of security software for Macs aren't stuck with this problem, so it's a slight concern that F-Secure's pre-release testing in the case failed to pick up potential problems, even though its handling of the problem once it manifested itself was open and praiseworthy.

(ElReg)