In many instances, the actor converted the cryptocurrency into BTC, Tether, or other forms of cryptocurrency – a process known as “chain hopping” – in order to obfuscate the transaction path. As detailed in the pleadings, law enforcement was nonetheless able to trace the funds, despite the sophisticated laundering techniques used.
this is a perfect example of why we need schnorr signatures. without schnorr signatures, we won't have adaptor signatures, which are needed for trustless and properly obfuscated cross-chain swaps.
http://diyhpl.us/wiki/transcripts/layer2-summit/2018/scriptless-scripts/The hacker stole nearly $2.5 million and laundered it through over 100 accounts at another virtual currency exchange.
they probably ran it through binance, with their 2 BTC withdrawal limit on unverified accounts.
All in all, the Justice department is looking to forfeit 280 accounts but how do they know those accounts belongs to the NK hackers or the Chinese launderers?
it's probably due to a distinct, repeating pattern involving the same actors. chainalysis has blogged before about a niche in the chinese OTC markets for brokers that specifically cater to money launderers.
the justice department still technically needs to prove their case:
The claims made in this complaint are only allegations and do not constitute a determination of liability. The burden to prove forfeitability in a civil forfeiture proceeding is upon the government.