I turned on visibility of hidden files, through the terminal command, to do some easy work in Finder on a Mac OS X server. Once I did this I found that there was thousands of (literally) .xyz files on the desktop of the Administrator user.
I have only found that this may be a Chemistry file format, which seems rather unlikely in this particular situation.
Example file name:
Filesize ranges from 600B to 6MB, mostly around 100-300KB; they are in binary format and are hidden but appear to have been opened at some point about 2 years ago.
What is this file and where did it come from?