Microsoft Security Essentials removes Chrome from users' machines

Microsoft's rivalry with Google took an interesting turn on Friday, after the firm's popular Security Essentials tool began to erroneously identify Google Chrome as malware and start removing it from users' PCs.

Google's Chrome team wasted no time in responding to the incident by initially releasing a set of workarounds and then promising a Chrome update over the weekend.

"Earlier today, we learned that the Microsoft Security Essentials tool began falsely identifying Google Chrome as a piece of malware (PWS:Win32/Zbot) and removing it from people's computers," wrote Google engineering manager Mark Larson.

"We are releasing an update that will automatically repair Chrome for affected users over the course of the next 24 hours."

Microsoft was forced to admit in a security update of its own that the false positive identified Chrome as a piece of malware and caused the browser to be "inadvertently blocked and in some cases removed".

"Within a few hours, Microsoft released an update that addresses the issue. Signature versions 1.113.672.0 and higher include this update. Affected customers should manually update Microsoft Security Essentials with the latest signatures," the update continued.

"After updating the definitions, reinstall Google Chrome. We apologise for the inconvenience this may have caused our customers."

The malware in question is a password-stealing Trojan that "monitors for visits to certain web sites", according to Microsoft.

"It allows limited backdoor access and control and may terminate certain security-related processes," the advisory stated.