SamyKamkar developed this seriously cool project to wrest control of civilian drones away from their owners.
SkyJack is a drone engineered to autonomously seek out, hack, and wirelessly take full control over any other drones within wireless or flying distance, creating an army of zombie drones under your control.
Using a Parrot AR.Drone 2, a Raspberry Pi, a USB battery, an Alfa AWUS036H wireless transmitter, aircrack-ng, node-ar-drone, node.js, and my SkyJack software, I developed a drone that flies around, seeks the wireless signal of any other drone in the area, forcefully disconnects the wireless connection of the true owner of the target drone, then authenticates with the target drone pretending to be its owner, then feeds commands to it and all other possessed zombie drones at my will.
SkyJack also works when grounded as well, no drone is necessary on your end for it to work. You can simply run it from your own Linux machine/Raspberry Pi/laptop/etc and jack drones straight out of the sky.
You can get more details and download the code on Samy’s GitHub page.