Oh, this stuff is fun. In high school, I made a WScript that prompted user "Network timed out on line #6. Please re-enter password:" and would surreptitiously record it. I put this on a floppy, popped it in when someone in the library went to the printer, waited, came back and said, "sorry forgot my floppy; can i get it, excuse me". Didn't use it maliciously; usually would just modify the folder settings on their home drive on the network to have repeating images of Pokemon as a background image. I suppose this all sounds quite devious in writing.