I just came across this today. What I did was remove Contra Virus and xpuupdate.exe from the start-up using msconfig. I then searched the registry for incidents of contra virus and removed them. After that, I found xpuupdate in the c:\windows\system32 folder and deleted it. I am running a Spybot check right now to confirm it's gone, but the icon in the system tray is now gone.