How do you know it's a worm?
It's is more likely to be spyware. Download the program and run it: http://download.com.com/3000-2144-10194058.html?tag=lst-0-1
TpT give this one a shot: http://housecall.trendmicro.com/
it's webbased
Open source (free) solution here: http://clamwin.sourceforge.net/
We use ClamAV here on the servers.