At this point, the attacker used a Wasabi wallet, which mixes many transactions together in order to obscure the funds flow in a process called a CoinJoin. It was thought that the bitcoins spit out on the other side of a CoinJoin were impossible to trace back.

While at that time, it may have been sufficient to turn the trail cold, with this news, Chainalysis is disclosing for the first time that it is able to de-mix such transactions.

When the attacker used Wasabi, they must have felt that their bitcoins had been sufficiently laundered. However, that was no longer true once Chainalysis’s technology improved over time.

In the end, my years-long effort unspooled in a few weeks. I feel confident about the evidence, which my sources also felt was extremely strong. Once we had everything, they marveled: "The evidence is never this good."