And it makes me wonder again, why South Korea?
Because it's easier to target a niche with this kind of attack, so by using Korean language software cracks and you have the advantage of wealthy victims and less competition as trying to infect users on a global scale might not give the same results versus effort.
And just like other malwares that has been observed already, they deployed it through under the guise of who else, Microsoft products Microsoft Windows and Microsoft Office(so another reason not to used Windows OS and at least try MacOS or Unix flavored OS.)
Sorry but out of a thousand reasons not to use Windows this is not one of them.
Downloading a cracked version of windows is from start asking for trouble and it's no different from downloading some unverified shady Linux distribution from a website and not the official release.
If it would have been about an app or a game, sure, but this is not!