McAfee is promising to release a signature updates to its AV software later today in order to prevent a popular ISP connection manager programme from been mislabelled as Trojan horse code.

The false positive meant that some versions of ISPWizard, an internet setup program wizard, was labelled as the BackDoor-AKZ Trojan by users running the latest update of McAfee's AV software. The error was introduced with a McAfee AV update released on 1 September and only affected end users running the latest McAfee update and older versions of ISPWizard.

But when those conditions are met, ISPWizard will be unceremoniously ripped from users' systems. This means that several people are unable to connect to their ISPs because the software that they need has been automatically deleted by McAfee. ISPWizard is widely used by many small ISPs particularly in the US. Fixing the problem normally involves a call by end users to their ISPs, disabling McAfee and reinstalling ISP connection software.

Shoot first and ask questions later

Following our story on the issue yesterday, McAfee has come back with a response.

Lee Fisher, of McAfee's AVERT Labs, its anti-virus research arm, said: "Customers using the daily DATs already have the fix, customers with weekly DATs will get the fix Wednesday. If a customer contacts support/AVERT they are supplied an immediate fix, alternatively the customer can exclude the file through the user interface and the problem disappears."

ISPWizard developer Mark Griffiths said that McAfee's workarounds thus far only help people when files have already been deleted, too late in his opinion. He remains highly critical of McAfee's decision not to release a consumer update before now.

Griffiths told El Reg: "Regardless of how this problem came to be, I'm still very unhappy with their response to the problem and the coding of their software to "Shoot first and ask questions later" - i.e. to delete the file without any prior warning to the user. It seems to me that McAfee is trying to do it's best to shift as much of the blame for the original problem away from itself."

So why was ISPWizard mislabelled as malicious code in the first place? McAfee's Fisher has the following to offer: "This type of thing happens because the code is very similar in design or technique to known malware, and as McAfee now have the 'known good' file, the problem disappears forever. It's unfortunate that it's happened, but McAfee takes extreme measures to ensure these problems are kept to a minimum, scanning the DATs [AV signature files] for false positives against almost two terabytes (some 30 million files) of known good code."

Griffiths is scathing about this explanation. "I reject the claim that the code is similar in design or technique to known malware - my own analysis indicates that McAfee is matching on non code sections of the file. McAfee certainly didn't take any 'extreme measures' to fix the problem once they were informed of the problem either." ®

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