The hacker's wallet did not have any relation to the exchange. The hacker simply sent all of the funds to the exchange, which suggests that the exchange was the intended recipient of the funds. This could indicate that the exchange was the hacker's intended target, or that the hacker was attempting to convert the funds into a more liquid form by transferring them to the exchange. It is also possible that the hacker was attempting to hide the stolen funds by sending them to the exchange in order to make them more difficult to trace.
