Good insight. I have thought similar things. Here is where I get stuck...
Does Japan know?
Does Russia know?
Does China know?
Does South Korea know?
4 countries with wildly different interests with regards to North Korea. How could these countries be ok with CIA living next door?
U.N. being North Korea puppeteer is more likely to me. A permanent world wild card maintains the need for a U.N.
This would be the secret of all secrets. For your hypothesis to work (not attacking, just bringing up info)...
South Korea would have to not know or keep it's entire population in the dark and maintain family separations.
Japan to not know or tacitly allow its citizens to be kidnapped.
China to not know or be OK with funding a CIA effort through aid/trade.
Russia same as China.
So where I end up is CIA support is possible, but outright "fabrication" of North Korea isn't possible.
What is most likely to me is CIA support via U.N./Red Cross. Both of those orgs and their money can move freely.