North Korea has been maintaining its economy while carrying a burden of international sanctions for quite a long time now. Almost all of the sanctions on North Korea are caused by its political position and are mostly influenced by the US and the UN.
Sanctions, implemented by the UN, mainly concern economic cooperation. Here is a list of some of the prohibited activities.
The US sanctions cover a bigger number of individuals and businesses than the UN ones due to the infamous North Korean cyber attacks against the US.
The key points of the US sanctions are contained in the Summary of the North Korea Sanctions and Policy Enhancement Act.
Since March 2018 international relations between South Korea and the DPRK got better, which means that we can expect some more economic activity between the countries. Despite sanctions on North Korea being active, the fact that the country begins developing its relationships with South Korea means that mutual economic activities may happen with more and more countries and North Korea is becoming more appealing for entrepreneurs.