How to remove MRT (Malware Removal Tool)? Note: I have already read MRT Process using large unbounded amount of memory (but here the context is different: &quot;I'd rather not remove it&quot;) and a few similar questions/articles like MRT is peaking my cpu, but a good complete solution was not easily findable.
On my Macbook Pro with High Sierra, the CPU fan was making a loud noise, and after doing top in Terminal, I noticed that a process called MRT was using ~100% CPU.
So how do I remove MRT (Malware Removal Tool)?
Removing Apple's Malware Removal Tool is not a good idea, so it's better to figure out why it's running high.
Also, 100% is a per-core figure, so on quad-core i7, you can use up to 800% CPU. Various OS processes, like Spotlight, will use similar levels of CPU for short periods.
MRT may use significant CPU for a short time while it does its job: downloading malware lists from Apple, and then checking/removing anything on that list.
If you have got a 'runaway' MRT process, then that might indicate that it is trying (but not succeeding) to remove some malware. You could try using MalwareBytes to check and remove anything on your disk, as suggested on the other thread.
At worst,  I would just recommend restarting, rather than disabling SIP and killing MRT, both of which severely reduce the security of your Mac -- particularly if malware is already on board.