Sophos false positive detection ruins weekend for some Windows users

A bad malware signature caused Sophos antivirus products to detect a critical Windows file as malicious on Sunday, preventing some users from accessing their computers. Because the file was blocked, some users who attempted to log into their computers were greeted by a black screen. Sophos issued an update to fix the problem within a few hours and said that the issue only affected a specific 32-bit version of Windows 7 SP1 and not Windows XP, Vista, 8 or 10. "Based on current case volume and customer feedback, we believe the number of impacted systems to be minimal and confined to a small number of cases," the company said in a support article. One Twitter user who was affected by the issue said that he highly doubts only a small number of customers were affected, while another one reported that he's been on hold trying to reach Sophos Support by phone for over two hours. "An email would have been nice," one user told Sophos via Twitter.