Original URL: http://www.theregister.co.uk/2008/10/16/avg_zonealarm_trojan_false_alarm/

AVG tags ZoneAlarm as Trojan

AV software meets firewall, has meltdown

By John Leyden

Posted in Security, 16th October 2008 14:41 GMT

A dodgy anti-virus update from AVG wrongly flagged up the popular ZoneAlarm firewall as a Trojan on Tuesday.

The mis-firing AVG definition file tagged components of ZoneAlarm as infected with the Agent_r.CX Trojan horse and quarantined important files. As a result users running the popular antivirus package alongside security suite software from Check Point were left with a malfunctioning firewall, mystery infection reports and an inability to re-install their ZoneAlarm software.

The problem cropped up on ZoneAlarm support forums and persisted into the early hours of Tuesday morning, before AVG issued an update that fixed the false alarm. Prior to that Zone Alarm users hit with the issue were able to get around the problem only if they knew how to add the directory path for Zone Alarm as an exception to anti-virus scans.

An AVG spokeswoman explained: "We did accidentally tag Check Point’s Zone Alarm as a trojan. The detection was out for approximately 7.5 hours. As soon as we were notified of the issue, it was resolved and added to our whitelist. We were made aware of it around 3am and the issue was addressed and resolved within a few hours."

Faulty anti-virus definition files crop up across the industry from time to time. The AVG case is mainly notably in that involves a combination of popular security packages that a sizeable minority of users are likely to run alongside each other. More commonly false alarms cause problems when they label Windows systems files or commonplace JavaScript apps, for example, as potentially malicious. ®