I have an X11 key listener. When someone reports a problem and they have access to the internet, I have them type "__medxremotedebug". An ngrok process is start

I have an X11 key listener. When someone reports a problem and they have access to the internet, I have them type "__medxremotedebug". An ngrok process is started, the machine beeps to notify the user that the backdoor is open. I then login to ngrok.com, see the tunnel and connect to it. All the units have a public ssh key and only I have the private key. This has saved me and my customers so many times.