As a reward, the attacker received 2 million of the tokens.
On Friday, the attacker who stole 20 million Optimism (OP) tokens returned 17 million of them. Over the span of 17 transactions, the funds were transferred to an address belonging to Optimism, the Ethereum rollup provider.
The attacker kept 2 million tokens as a reward, as per Optimism’s tweet.
Prior to returning the tokens, the attacker wrote an on-chain message to Ethereum co-founder Vitalik Buterin, expressing their intention to return the entire 18 million OP in their control.
“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.
Stay Optimistic! “
According to Optimism, the attacker cashed out 1 million OP and sent another 1 million to Buterin, who is seeking to return the funds. As per blockchain data, the attacker still had 1 million tokens in his wallet, worth nearly $900,000.
With its speedy transactions and minimal costs, Optimism is a layer 2 rollup chain for Ethereum that helps scale the network. Last month, it introduced the OP governance token in an attempt to move towards greater community control.
The attacker acquired OP tokens that were intended to go to Wintermute, a crypto market maker who collaborated with Optimism for “liquidity provisioning services” prior to the token’s release.The problem arose when Wintermute gave Optimism an Ethereum address instead of an Optimism address to receive the loaned funds.
The attacker built up their own wallet at the address where Optimism sent out the 20 million tokens before Wintermute could recover them.
Wintermute announced in a statement two days ago that if the cash was returned within a week, it would not take legal action against the attacker.