The Optimism hacker who stole 20 million OP tokens has returned 17 million tokens to the company. During the launch of a native OP token for Optimism’s DAO, a hacker took advantage of a company error and stole 20 million tokens. It seems like the hacker has had a change of heart, as blockchain data from Etherscan shows that the tokens were sent back in 17 separate 1-million transactions yesterday. The attacker also sent one million OP tokens to Ethereum co-founder Vitalik Buterin. The attacker now has 2 million OP tokens in their custody after sending 18 million tokens to Optimism and Buterin. About 1 million of these tokens have been exchanged for ETH and sent to Tornado Cash for mixing. The Optimism Foundation has revealed in a post on Twitter that the 2 million tokens that have not been returned are now a bounty that will be paid back by Wintermute. In addition to this, it stated that it was currently working to retrieve the one million tokens that were sent to Vitalik Buterin. How Did The Attack Happen? The hacker gained control of the tokens due to an error between Optimism and Wintermute, a crypto market maker contracted to distribute the 20 million OP tokens. The wallet address Wintermute used to receive the tokens was inaccessible because of a layer-1 and layer-2 issue between the two companies. Optimism runs as a layer-2 and Wintermute’s layer-1 wallet was yet to be synced to Optimism’s layer-2. The hacker took advant...