A volume control monitoring app in HP laptops, according to this, monitors *all* keystrokes to see if the volume up/down buttons are pressed, and keeps an unencrypted plaintext log file of every keystroke, *and* has an API to hand over data realtime.
https://boingboing.net/2017/05/11/thanks-conexant.html https://awoo.space/media/iRTXSzhWzcM1jm9lp28