Have look at this too:
http://www.symantec.com/avcenter/ven...e.warning.html
It does seem that sulfnbk.exe is not a virus but is an important file working in the background of W9*; but I can't find it in Win2000.
If you deleted it you can get it back using Symantec's guidance.
[This message has been edited by fobotcso (edited 01 June 2001).]