Tool to sort Activity Monitor: legit or suspicious

At https://objective-see.com/products.html there are (free) tools available to see security related process information (persistent processes, process hierarchy etc.)

There is a suite of security features (like GateKeeper), including malware removal tools (xProtect and – appropriately named – MRT) built into macOS. These are updated silently and regularly in the background independent of "regular" macOS updates.

If you want to see more information/the current status of all these built-in tools, have a look at the applications available at: https://eclecticlight.co/downloads/.