I wouldn't even think of this as being shady. If you're a firm based in a country where it's politically/legally ok to work with people in North Korea, and someone (from a country where it isn't) employs you to do some work, and doesn't contractually require you to do the work yourself, and you know you can get someone else to do it for much cheaper, but still meet all the requirements... why wouldn't you do that? It's not shady at all; it's just... smart. The client is getting the product for the agreed-upon price. They're effectively paying for your ability to work with people that they can't work with.