This is a virus. There's info here
http://www.gnutellaforums.com/showth...threadid=39612

and point 4 here
http://www.gnutellaforums.com/showth...threadid=41432

You should read the whole second thread, it has lots of advice & info about virus problems. There's also a link to norbiesworld. If you go to his site & register (it's free), he'll be able to help you get rid of the virus.
Please make sure you have a good AV program & scan a file before opening it