The hosts of a VICE documentary were able to visit a computer lab [1] last year, and looking at the start button(?), it looks like an older version of Red Star OS.
Perhaps the reason is similar to the (apocryphal) tale of how the Tu-4 was manufactured with bullet holes copied from a captured, battle-damaged B-29 because Stalin said to copy it exactly.
[1]: http://youtu.be/IrCQh1usdzE?t=15m43s