Unknown excel backup files created in network directory
 

Does anyone know why there are several unknown files created after a user
runs an Excel spreadsheet from within a networked directory? The files are
basically backup files and have strange names associated along with no file
extensions. If you click on the file and choose to open with Excel, the file
opens up the Excel spreadsheet that the user was currently working on. This
is an example of what the file name looks like within the network directory
-- 0DAFE500 or 4CD55000. I've looked at the excel options and there is
nothing that's checked as far as backup or autorecover.

Thank you in advance...