Soldato
Hate to be that guy, but no proof has ever been presented that the rebels used a Russian supplied Buk and not one of their own. Obviously we know it was statistically likely to have been a Russian one as the rebels only had half a dozen or so and the Russians are rumoured to have sent dozens more into the area but we don't actually know for sure and probably never will. Not that it's that important as what happened wouldn't have without Russia's decision to back the eastern rebels, Putin and Russia are definitely culpable.
It was Russian.