Quote Originally Posted by stanav View Post
Delete all temp files and temp internet files, then using system restore to restore your computer to a previous state normally will get rid of this sick fake virus warning. As for how your computer gets infected by this trojan: just by browsing the Internet. If you're visiting a webpage that is infected by malware, there's a great chance that your computer is infected too. Those sick bastards browser code injection techniques to insert malicious code into the page's source (for example, injecting an invisible iframe which contains code to do bad stuff) and bang, you get infected if you happen to visit that page.
these exploits are browser-dependent however. An exploit that works on IE will fail on firefox or opera. In IE, if you leave UAC on, you will get a prompt to install xml addons. NEVER let it install. once installed, malicious code no longer even needs permission to run.

I also have seen a recent trend where spyware writers have bought banner ads with malicious code in the ad. That antivirus 2009 crap? I got redirected to there once from microsoft's website!