With the right approach, the possibilities are almost endless. Already, previous versions of the Rubber Ducky could carry out attacks like creating a fake Windows pop-up box to harvest a user's login credentials or causing Chrome to send all saved passwords to an attacker's webserver. But these attacks had to be carefully crafted for specific operating systems and software versions and lacked the flexibility to work across platforms. The newest Rubber Ducky aims to overcome these limitations.
It ships with a major upgrade to the DuckyScript programming language, which is used to create the commands that the Rubber Ducky will enter into a target machine. While previous versions were mostly limited to writing keystroke sequences, DuckyScript 3.0 is a feature-rich language, letting users write functions, store variables, and use logic flow controls (i.e., if this... then that). That means, for example, the new Ducky can run a test to see if it's plugged into a Windows or Mac machine and conditionally execute code appropriate to each one or disable itself if it has been connected to the wrong target. It also can generate pseudorandom numbers and use them to add variable delay between keystrokes for a more human effect. Perhaps most impressively, it can steal data from a target machine by encoding it in binary format and transmitting it through the signals meant to tell a keyboard when the CapsLock or NumLock LEDs should light up. With this method, an attacker could plug it in for a few seconds, tell someone, "Sorry, I guess that USB drive is broken," and take it back with all their passwords saved.