this sounds odd. other reports said that the final landing for these drones is done with a local, direct link (which was a possible candidate for how it was hacked), but this article implies (if i am reading it right) that by faking GPS it was misled into thinking it was landing in its normal place. also, in the linked article it says that the underbelly was damaged because the altitudes differed by a few metres, but…
Sounds plausible to me.
Russian-made GPS jammers have been reportedly on the market for over a decade now.
Alternatively, it might also be enough to simply fly your own plane and GPS receiver some relative distance away from the drone and rebroadcast the signals received from there with a higher strength. Of course, this type of forwarding attack could end up with the Iranians landing a plane of their own at the US base. That would be bonus points for style. :-)