One less to have to write if you want to do evil. HP -oh nice, just have to enable their builtin keylogger.
This answer explains and also has a link to ms with more detail on how it’s blocked: https://stackoverflow.com/questions/3169675/how-to-use-setwi...
Malicious keyloggers are used all the time of course, but I believe they all require some sort of exploit or way to effectively gain admin privileges.
The answer was about intercepting messages sent to an already escalated process (i.e. monitoring administrator processes from a user's context, even if they're technically an administrative user).
It works for one user context process monitoring another user context process. It doesn't work for IE or Edge due to LowPriv context isolation.