My guess - originally from Iran - being used by Hezbollah in Lebanon....
I don't think Islamists in Sinai have that kind of tech...MANPADs maybe - but drones??

Egyptian Government might have a really really incompetent drone pilot - looking for Sinai Jihadis in So. Israel...

Who was the Egyptian airline pilot who flew the commercial airliner into the Atlantic b/c he was depressed? Maybe he has cousin in Egyptian Air Force....