Security firm PeckShield initially suggested the issue might have been with QiDAO, which creates the $MAI stablecoin. The vulnerability is not with their project, although it's possible that the theft will impact the collateralization of their stablecoin.
Adding to the recent string of oracle manipulation attacks is an attack on the miMATIC ($MAI) market on the QuickSwap decentralized exchange. An exploiter was able to manipulate the spot price of assets to borrow funds, ultimately making off with 138 ETH ($188,000) that they mixed through Tornado Cash. The vulnerability was due to the use of a Curve LP oracle, which contains a vulnerability that was disclosed by a security firm earlier that month.