Popular antivirus service Webroot mistakenly labeled key Microsoft Windows system files as threats Monday, causing the misidentified files to be removed and an untold number of PC computers to be shut down, NBC News reported.
Webroot said it had released an update that caused the malfunction, which lasted for about 13 minutes worldwide. As of early Tuesday, Webroot was still working to resolve the problem, according to the company's website.
Tens of thousands of businesses and millions of people at home use Webroot. Some customers took to social media to complain.
Webroot didn't respond to NBC News' request for comment but said on its website that the company "has not been breached and customers are not at risk."