Well, thats a polymorphic virus !
See this for removal and info,
*securityresponse.symantec.com/avcenter/venc/data/w32.pinfi.html
Also u can d/l the update at this site :
*securityresponse.symantec.com/avcenter/defs.download.html (direct i guess)
or indexwise :
*securityresponse.symantec.com/avcenter/download.html
Well to remove that virus u need ur defn updated.
well tis a pain but is helpful and also this month has defns buddie
see this for details :
*www.thinkdigit.com/interactivecontents.html