Trylonian

Trylonians were known to the Eleventh Doctor as a "nasty species". They once tried to siphon everything the Doctor knew about other alien races for their conquests by using a Trylonian Brain Drain Machine on him. The Doctor overloaded their war computer with his mind and proceeded to defeat them using his sonic screwdriver. (COMIC: The Birthday Boy)

They invaded a planet and destroyed the local civilization. A few survivors stole a Brain Drain Machine and fled to Earth to find someone to stole ideas from to fight back the Trylonians. (COMIC: Convention Special)