The level of persistence these guys went through to phish at scale is astounding—which is how they gained most of their access. They’d otherwise look up API endpoints on GitHub and see if there were any leaked keys (he wasn’t fond of GitHub's automated scanner).
https://www.justice.gov/usao-wdwa/pr/member-notorious-intern...
They themselves are likely to some extent the victims of social engineering as well. After all who benefits from creating exploits for online games and getting children to become script kiddies? Its easier (and probably safer) to make money off of cyber crime if your role isn't committing the crimes yourself. It isn't illegal to create premium software that could in theory be use for crime if you don't market it that way.
But he shrugged it off.
I bet there are quite a few shops online that may sell gift cards that are used in money laundering schemes. Bonus points if they accept bitcoin.
But those are all quite implicitly used by cybercrime. I can imagine there are quite a few tools at their disposal that are much more explicit.