Hey Hey,

No offence to your "this is unlikely to be user related" but I've found that when that is said.. it usually is user related. Also no offence to your abilities as a programmer but being able to program doesn't mean you know **** about the actual computer... Two very important things to keep in mind.. (Spyware/Malware is all user related... an uneducated user)... This is not meant to be disrespectful but to be enlightening.

http://www.sysinternals.com/Utilities/Filemon.html.

Above is a handy utility that lets you track all activities involving your file system. It's entirely possible that he file is supposed to be there... Microsoft applications are notorious for making back-ups (or simply copies if you prefer as it's not really a back-up) of currently accessed files... If the application/system should happen to crash while one of these files are open... the back-up is never cleanly removed and remains behind. It's possible that this was a back-up of the address book and Outlook, OE, or whatever you may use and a crash left the back-up behind.

Check and see if you have any hidden services or executables.. I prefer tasklist and tasklist /svc from the command line for these purposes.

If you aren't finding any additional services or binaries, and you know your OS is up-to-date then I'd run MS Anti-Spyware, SpyBot S&D and AdAware... and see if they uncover anything.. If you have a Host Based IDS you may want to check for registry changes and if you have a firewall or network IDS you could check for large quantities of email being sent (since it looks like an address book)... If you are not finding anything is these errors, I'd chalk it up to user related or OS related.. Windows is notorious for things randomly appearing that weren't previously there.

Peace,
HT