This is huge, you can get redirected from any site that embeds a youtube video. What's that about 98% of sites?

This issue effects IE, FIrefox, and Chrome. Possibly others but these are definitely effected. In Vista there is an accept dialogue box after you are redirected, not sure about other versions of windows.

I would suggest not clicking on any embedded videos at all for now. Visiting youtube is fine, there is nothing wrong with the files themselves it's an exploit taking advantage of the browsers redirect from embedded files on external sites.

This is a nasty virus that's installed, if you are infected you'll more then likely be reinstalling windows to get rid of it. It installs so many trojans, keyloggers, and viruses that's it hard to be sure you have removed all traces.