Monitor keyboard access on the Windows lock screen

Question

I don't do this very often, but every time I lock the screen in Windows [Win+L], the keyboard (and sometimes the mouse) stops responding and it goes straight into the password field and it starts typing random characters (like Mud2Cx22).

It looks like it only does it on the lock screen (I assume it would interfere with normal use if it were to do it always). Is there a way to monitor if and when my keyboard is sending data, and what is triggering it?

I don't see any suspicious connections on the PC or the router. I do full malware scans daily, and Windows is updated... I'm out of ideas...

Answer 1

Try switching out all current USB devices. Though rare, there are USB devices used for targeted attack, such as keystroke injection.

Another possibility is that a nearby device is using the same protocol as a wireless keyboard or mouse, so test this by using wired-only devices for a while, or use different devices with their own wireless dongles.