In a note to the Poly Network team, the attacker referred to the saga as "one of the most wild adventures in our lives."
Ethereum blockchain transaction records confirm the transfer of 160 ETH (about $480,000) to the "Poly Network Exploiter 2" wallet address.
"WHAT A FUNNY GAME," the Poly Network attacker wrote into a transaction on the Ethereum blockchain.
The attacker now says they are considering accepting the $500,000 bounty offered by Poly Network as a reward for returning the funds, and using it to pay anyone else who can hack the DeFi site.
The largest cryptocurrency by market value was trading close to its highest level in more than two months
Analysts said the market doesn't have much of an appetite now for bitcoin above $46,000 or for a massive selloff.
If computers will continue to do more important things, we'll require those programs to be secure. Learning what not to do is one way there.
$342 million had been returned as of 08:18 AM UTC Thursday, according to a tweet by Poly Network.
The hacker sent millions of dollars back.