Here is out of ps aux| grep atd on my server.
apache 1299 0.0 0.0 5328 2768 ? S 08:21 0:00 /usr/sbin/atd
root 15407 0.0 0.0 4020 708 pts/3 S+ 11:02 0:00 grep atd
apache 16506 0.0 0.0 5328 2808 ? S 08:52 0:00 /usr/sbin/atd
The process atd is not even present on its physical path, but the above path shows that it is there and its running under apache. how to track and detect its activity?