Someone earlier, (Very ex BA?), mentioned a darkened cabin and crew in their bunks. It is only a six hour flight, highly unlikely the cabin crew would have anytime for bunk rest, especially in the premium cabin(s) where hijackers tend to sit.
So much information has been given out to the general public about transponders, the various emergency codes etc. that any hijacker these days will, on gaining access to the flight deck, almost certainly switch it off.
MAS seem an unlikely target for a hijacking.