Perhaps. But, unless this is a suicide mission, how do you extract the troops once they completed their task? A parachute jump is a one-way path.
Any such action, if discovered - or even if admitted to - would be an act of war even if no shots were fired. NK is anxious to get a casus belli on their side. NK is currently (as usual) in bad shape, with drought reported. Kim-in-Charge may run out of his own people in a few years, so he may want to attack someone, anyone, just because otherwise he'd be all alone in North Korea, surrounded by dead bodies and ideas of Juche.
People posted night maps of NK. It is indeed dark. However this doesn't tell anything about the radars and other ways of watching the skies and the land. In fact, light on the ground is not helping you at all. Those HALO jumpers may be jumping right into a prison camp and they wouldn't know it. You cannot see a weak light, such as a kerosene lantern, from a weather satellite. Bright light spots on the ground are cities - places where megawatts of power are burned. Night lighting of a military base can be all under 100W. Infrared lighting of security zones, along with night vision goggles, is the way to go.
My personal opinion is that no jumps were done; if there are reconnaissance missions afoot, they are conducted in a smarter way. For example, $10 passed to a local man can do more than a platoon of US soldiers. Foreign soldiers would be very hard to mistake for North Koreans - at least because they are not fainting from hunger, let alone their language, skin color, and other differences.
My guess? Indig SK swimmers.