Tornado Cash suffered from a governance attack and 370 ETH was taken. Through a malicious proposal, an attacker granted themselves 1,200,000 votes. Once the proposal was passed by voters, the attacker used the emergencyStop function to update the proposal logic to grant themselves the fake votes. From this the attacker is able to withdraw TORNs and sold them. Approx. 483k TORN were taken and 379k was sold into ETH and deposited into Tornado Cash.

The attacker was able to pull this off b/c the voters blindly approved the proposal without examining the underlying logics and the attacker effectively obfuscated the logic by falsely naming the function and used a trick combining CREATE/CREAT2 to hide the actual intent of the logic (refer to Blocksec post for additional discussion on the trick).