had a bit of a run in with some spyware on my pc

at random intervals a file called www.exe appears in my c:\documents and settings\steve buck\ folder. This file then executes (randomly) in a dos prompt style window. If the pc is left unattended for long periods of time, it keeps executing this file over and over again so I end up with a load of windows on the screen. The more that are open the slower the pc gets (obviously) and my network grinds to a halt (in particular, ICS and remote desktop). I suspect the exe is pinging an address over and over.

I've tried deleting the file, i've even locked out my self permissions from executing the file. And it just keeps reappearing and executing.

Ive ran virus scans (Norton 2004), and 4 different spyware apps (microsoft, search & destroy, adaware, adware) and although they pick up a lot of new spyware appearing on my pc (3 - 6 items per day) they never pick up this www.exe file.

I've been through the registry and there's no references to www.exe.

NExt stage is to just rebuild the pc. But before I do, my last cry for help if anyones come across this one or can reccomend a better spyware app than the ones I've tried.