The Lazarus group has been responsible for different campaigns and variations of RATs, Trojans, backdoors, and malware in general. Some of the names given to malware created by Lazarus are FALLCHILL, Destover, Hangman, Volgmer, and Manuscrypt, among others. For someone who has not personally analyzed these different malware families, a lot of the samples associated with each malware could appear to be completely different, but if you examine them at the code level, you can see that these attacks are most likely different components of the same framework that has been pieced together or upgraded.