According to CoinMeta, as reported by Protos, a contract left by MakerDAO for auctioning keeper was attacked due to a lack of access control in the 0x8804d1de function. The attackers stole 200 ETH, worth over $500,000. This contract was involved in the liquidation crisis in March 2020, and the attackers utilized four unsettled transactions of 50 ETH each to steal funds, transferring them out in batches of 10 ETH each through Tornado Cash.