Part of macOS
XProtect…Malware protection
○ Leave it
Checks apps and files against Apple’s list of known malware.
What it is
Apple’s built-in protection. It scans apps when they open and from time to time in the background.
Why it might be busy
After its malware list updates, or when you open a new app. Usually a few minutes.
If you stop it
macOS starts it again straight away. Leave it.
The verdict
○ Leave it. Part of macOS, or something that starts again by itself. You never need to close these.
In Activity Monitor
XProtect…Xprotect…xprotectd…
… means any name that starts this way.
From Procession’s guide, in the words the app shows.