Bluenoroff or APT38, more commonly referred to as Lazarus Group is a threat group which has been tied to the North Korean government since as early as 2009 primarily being financially motivated utilizing malware custom built for each target.
Early on, the threat group gained notoriety for cyberattacks such as Sony Pictures Hack in 2014 and $81M Bangladesh Bank heist in 2016 and in more recent years has shifted focus to targets in the cryptocurrency industry.
Analytics firms such as TRM and Chainalysis release annual reports summarizing crypto related incidents linked to DPRK and since 2017 they estimate between $3B to $4.1B has been stolen.