14 DAY TRIAL // BitDefender customers were affected by a faulty antivirus update, which incorrectly tagged critical system files as malicious, over the weekend. The problem affected 64-bit Windows versions and left computers unable to boot.
Beginning Saturday evening, BitDefender's support forum started being flooded with reports from users, who claimed their antivirus indiscriminately detected hundreds of files as being infected with Trojan.FakeAlert.5. "EVERY file that is trying to run is getting quarantined. Windows Explorer and even Bitdefender update itself is being quarantined," one of the first complaints reads.
Information sent to us by the antivirus vendor suggests that this was a quality assurance accident. Detection routines normally undergo a validation process, which involves scanning a known clean set of files. If any detection is triggered during this step, the update is automatically rejected for being faulty.
"The incident was due to a fault in the validation software. A faulty update was uploaded on our update servers. The same update was correctly processed and rejected for the 32bit products," the company explained in an e-email sent to our editorial office. The buggy definition file was publicly available from 8 AM to 11:30 AM PST on Saturday.
A patch that will automatically restore the erroneously quarantined files has been released. There are different versions of this patch along with installation instructions for the BitDefender 2010, BitDefender 2009, BitDefender Client Security (for bussinesses) and BitDefender Security for File Servers products.
Deploying the fix is rather straight forward for users who did not yet restart their computer. However, customers who are not longer able to boot into their OS will have to perform a system repair first, an operation that might have to be repeated multiple times for a complete success. Windows XP 64-bit users in particular who find themselves in this position are encouraged to contact BitDefender Customer Care in order to determine the best course of action.
"We apologize for this error and we will work to prevent this from occurring again in the future," the company said in a press release. However, apologies are probably of little comfort to those unfortunate IT staffers, who were faced with the daunting task of repairing hundreds of computers when they came to work on Monday.
That being said, BitDefender is certainly not the only antivirus vendor to mess up updates and crash their customer's computers. Back in June 2009, we reported that McAfee issued a buggy service pack to VirusScan Enterprise 8.7i customers, which deleted critical system files. In March 2009, a faulty definition update from ESET quarantined several Windows components, while in November 2008 a similar incident at AVG left non-English Windows XP computers unbootable.