Why bother to hijack it? You can buy a plane and paint it however you like.
Boneyards are everywhere:
http://jalopnik.com/the-ten-most-unbelievable-airplane-junkyards-in-the-wor-1464369226
http://www.airplaneboneyards.com/commercial-aviation-airplane-boneyards-storage.htm
http://io9.com/the-worlds-most-bizarre-aircraft-graveyards-511526945
If you’ve got the cash (like if you were backed by Saudi oil) you can get a plane with varying levels of paperwork. Park in a place with bad weather and do a little insurance fraud and you can even make it so nobody knows you have a plane.
You’ll notice a bunch of those boneyards are in Russia, if Putin wants a plane Putin gots a plane.
The hijack angle just never made sense. It’s a harder way to get a plane, with a lot more complication and a lot more opportunities for it to go wrong.
The hijack angle is making more sense with every passing day that the airliner goes missing.