@maxdog,
It's possible because this aircraft has a fuel tank storage capacity of 138,898 litre (36,693 US gallon) with a fuel economy of 0.113 kilometres / litre (0.23 nautical mile / gallon).
Your idea that it might be hoax is interesting, since that flight had been announced months ago, tere were more tah 50 passengers on board, the flight could be followed live on flight trackers, videos have been posted ...
Actually it wasn't a test, if there was enough fuel for such a flight but to see, if such a long flight is doable for crew and passengers.