Security concern
 

Hello. I was wondering if there is anything to be concerned that there is a security breech when my computer is on running linux and my hard drive starts to think (spin) when I am not doing anything. Bare with me for I am a newbie.
Thanks.

some process running in the background I would imagine.

try running top and see what's running.

How do I do that ?

you open up a terminal and type top
hit ctrl+c to close it