Microsoft's security tools erroneously marked Google's Chrome Web browser as a dangerous piece of malware and removed it from approximately 3,000 Windows machines today (Sept. 30).
Chrome users began complaining this morning on support forums that Microsoft was flagging the Google Web browser as "Win32/Zbot," more commonly known as Zeus, a dangerous Trojan that has helped cybercriminals steal millions of dollars from people's bank accounts all over the world.
One such complaint found by ZDNet read, "This morning, after I started up the PC, a Windows Security box popped up and said I had a Security Problem that needed to be removed. I clicked on the Details button and saw that it was 'PWS:Win 32/Zbot.' I clicked the Remove button and restarted my PC. Now I do not have Chrome."
It turns out faulty updates to two Microsoft security programs, Security Essential and Forefront, were responsible for the problem. Microsoft wrote on its Malware Protection Center blog that it has already fixed the problem.
"On September 30th, 2011, an incorrect detection for PWS:Win32/Zbot was identified and as a result, Google Chrome was inadvertently blocked and in some cases removed," Microsoft wrote. "Within a few hours, Microsoft released an update that addresses the issue. Signature versions 1.113.672.0 and higher include this update."
Microsoft apologized for "the inconvenience this may have caused our customers," and urged
affected users to manually update Microsoft Security Essentials (MSE) with the latest signatures and to reinstall Google Chrome.