I know that if you have physical access to a computer, it's pretty much owned. But the reason I wanted to make a rubber ducky payload of this old backdoor is that you only need a few seconds to install the backdoor. I.e when the victim leaves his/hers computer unattended without putting on screen saver with password, you put in the rubber ducky and install this payload. After this you can a) press the SHIFT key continuously for 5 times or B) Alt+Shift+PrintScreen which will open a command prompt with system privilege. Simple and cool :-) Make sure to take a backup of the original sethc.exe.