According to a tweet from Optimism, 2 million tokens were retained by the attacker as a bounty.
Before returning the tokens, the attacker sent an on-chain message to Ethereum co-founder Vitalik Buterin stating their willingness to return the full 18 million OP in their possession.
“Hello, Vitalik, I believe in you, just want to know your opinion on this. BTW, help to verify the return address and I will return the remaining after you.
And hello Wintermute, sorry, I only have 18M and this is what I can return.
Previously, the attacker cashed out 1 million OP and sent an additional 1 million to Buterin, who is working to return the funds according to Optimism. At press time, 1 million tokens, worth close to $900,000, remained in the attacker’s wallet, blockchain data show.
Optimism is a layer 2 rollup chain for Ethereum that helps scale the network with its quick transactions and low fees. It launched the OP governance token last month in a bid to shift towards greater community control.
The attacker managed to get a hold of OP tokens that were supposed to go to Wintermute, a crypto market maker that partnered with Optimism for “liquidity provisioning services” in the run-up to the token’s introduction. Trouble came when Wintermute mistakenly provided Optimism with an Ethereum address, rather than an Optimism address, to receive the loaned-out funds.
Before Wintermute could retrieve the funds, the attacker set up their own wallet at the address where Optimism sent the 20 million tokens.
In a statement released two days ago, Wintermute said it would not pursue legal action against the attacker if the funds were returned within a week.
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