North Korean cryptocurrency hacks are a bit distinctive. Rather than finding logical bugs in contracts, they tend to use traditional spearphishing / social eng to get targeted people to run malware which they try to pivot to stealing keys / access credentials. Then after a hack, most crypto hackers try to obfuscate and store their stole coins on chain somewhere. North Korea already has a large and practiced money laundering network, so after a hack the money immediately starts going to hundreds of different places in the real world, perhaps to mules or to faked accounts in Southeast Asia.

Google: "North Korea Ransomware"