OK, I'm only trying to be funny with the title. 
That's the nickname of this virus. It's called Yay virus, because
it caused Yay popups.
This one is a real nasty. It overwrites nearly all .exe, so if you
run into problems with running certain programs, it's probably
being overwritten.
One sign of this is the Yay popups. If you have those, you do have
the Yay virus. And if you run into problems with your applications,
you will have to uninstall them.
The Yay virus seems to be gone when the bad exe was uninstalled
(like Google Toolbar, see link below)
http://sg.answers.yahoo.com/question/index?qid=20070110141133AAdOksi
I don't know if reinstallation will bring back the virus... all of
them in the link didn't reinstall it.
