'White hat' hacker returns almost all of stolen $600 million in crypto, but...

The hacker behind one of the biggest cryptocurrency heists at Poly Network, a cryptocurrency platform, has sent back most of it saying the digital tokens were stolen just "for fun" and that it was “always the plan” to eventually return them.

On August 12, Poly Network, a platform that allows users to transfer or swap tokens across different blockchains, said out of the $610 million stolen, $342 million of assets have been returned. Meanwhile, $268 million of assets (on Ethereum) has been locked in an account that requires passwords from Poly Network and the hacker to gain access.

The hacker, who's being hailed as a 'white hacker' on Twitter, has said the final key (to the remaining $268 million of assets) will be provided “when everyone is ready”.