Sorry guys - Sulfnbk is a hoax.  And a very old one too.
Please see
http://www.symantec.com/avcenter/venc/data/sulfnbk.exe.warning.html

   Yours truly,
     David Kinney
 

On Mon, 13 May 2002 MadCityKenners@aol.com wrote:

> I'll be darned . . . this virus DID show up on my computer; don't exactly 
> know where it came from, so I'm sending this warning on to everyone on my 
> list, even if I haven't emailed you in a long time ~ don't want it lurking in 
> my address book!
> 
>