This story gets more interesting and interesting with every day. I really hope it was hijacked and landed safely somewhere.
I bet you could get $500,000,000 ransom for the safe return of the plane, the crew, and the passengers. The plane alone is worth $100 million.
Half a billion buys a lot of military hardware on the open market.
Odds are they are dead, at the bottom of the ocean. Flying low enough to avoid radar will significantly shorten the range (denser air at low altitude, etc).
Better than being dead.