mrgray runs a script in the background (so there is no need to set up a cron job). There are several ways to do this, all are legitimate.
At the heart of the script is a command like the following:
This command shows all the processes being run, and it prints out the arguments of the commands that start the processes.
The script also contains a command like
This shows all the mount points and their associated devices. In this case, the Samba origin will show.
Last, but not least, the script may scan the whole file system periodically for interesting files.