Questions on hardware keyloggers will almost always reference the fact that they’re nearly impossible to detect. Unless the user notices them or you have dedicated security staff watching for them, these are foolproof, easy to install, and great tools to use. They are usually small devices connected between the keyboard cable and the computer that simply capture all keystrokes going by. Install one day and just wait— when you pick it up, it will be filled with all the access information you need. Just remember that the hardest part of using a hardware keylogger is the physical access required to install it: They’re not remote access, introvert-friendly, work-in-the-shadows tools, so you’ll have to actually get next to a system to put it into action.