If my Mac was hacked, how would I know? - Quora
how to check if my Mac has been hacked - Apple Community 2017-5-18
6 Signs That You’ve Been Hacked (And What To Do About It)
On macOS, go to Terminal and enter specific commands. You can find a tutorial here. If your webcam light turns on a few seconds after you reboot your computer, without launching any applications – you might’ve been hacked. If this is what’s happening, move on to the next step.