SniffMK is a simple utility designed to sniff mouse and keyboard events on macOS. It is based on code from Amit Singh's website
SniffMK was designed to facilitate malware analysis (specifically OSX/FruitFly which can simulate both mouse and keyboard events) See BlackHat/DefCon slides for details.
https://github.com/objective-see/sniffMK
Patrick Wardle - Objective-See