This was a targeted attack against a cryptocurrency exchange. The specific crypto happened to be Ethereum (ETH), but more importantly the hackers were able to identify and target the specific employees needed for their multi-signature transactions, and infect their machines with malware to alter the user interface and show different destination wallet addresses. The exchange Bybit has offered a 10% bounty which could earn whitehats up to $140 million for any funds recovered, but I would be very surprised to see huge success with the use of mixers and such.