I think everyone knows at least one movie where a hacker/agent/spy inserts a small USB device into the victims computer and the devices starts to do some magic hacking to deploy a backdoor, to deactivate the firewall and so on.
In this series of articles I will show how to use an Arduino to build an USB hacking device. I will start with some basic steps to get started and will continue to develop some tools to automate the process to create the firmware. To follow the steps you should at least have some basic knowledge on how to use and program an Arduino or similar microcontroller board.
If you're looking for an easy way to do USB pentesting you might prefer a prebuild device like the USB Rubber Ducky developed by the guys from Hak5.