From the FAQ at http://www.whatisthatfile.com/index.php?nav=faq :
"What Is That File is a simple help for you to identify any unknown files
on your computer. You can enter a filename and see if this file is a
dangerous trojan, malware, or simply a standard Windows file.
However, this application is not up to date with all trojans and malware
and it's not able to trace the latest virus warnings."
The service is available at: http://www.whatisthatfile.com/
Interesting. I tried a commonly infected file, "Britney_Spears.scr" but
whatisthatfile didn't recognize it, so when they say it's not complete
they mean it. As I typed characters it matched any files it knew to the
partial filename I had typed in real time, so that's pretty neat. I can
see this useful for identifying legitimate system files.
CIT Client Services
CALS Information Technology Office
University of Vermont, Burlington