If you had a skill to hack $2.3B you'd definitely found the way how to launder it. So many ways to do it: deep net, mixers, scam exchanges, OTC private deals, multiple wallets etc. I think they will be ok if don't make some stupid mistake which is possible too.
How on Earth does one even begin to launder $2.3 billion. They will have to have like 100 corrupt politicians in their back pocket. Really, you need government cooperation to launder that kind of money. And they probably can never travel outside the country where they cash out.