Media mention of religion in North Korea generally involves the arrest of some unfortunate foreign Christian who thought they could sneak a Bible or other evangelism materials into what is arguably the world's most repressive state -- which is saying something, given the number of horrific governments out there.
As for the existence of religion in North Korea itself, the default position for most journalists, including those on the religion beat, is that the nation formally (and oxymoronically) known as the Democratic People's Republic of Korea is officially atheist. On occasion, a more knowledgeable reporter may note that its official philosophy is known in Korean as Juche.
This recent New York Times piece does just that. Here's the pertinent sentence: "Juche, or self-reliance, is the North’s governing ideology."
Well, yes. But there's so much more that can be said. Including that some who study the sociology of religion consider Juche -- as politicized and seemingly secular as it is -- a "religious" ideology. Which means there's a "religion ghost," or unrecognized religion angle, hidden in some stories about how the North's oppressed population endures.