Decentralized perpetual futures exchange Ostium was drained of at least $24 million after an attacker manipulated its oracle system — a system that pulls in off-chain price data. After the attacker apparently gained access to the private key used to sign oracle messages, they were able to submit future-dated oracle reports that tricked the system into thinking trades were profitable.
The attacker siphoned at least $24 million USDC from the protocol, which they quickly swapped into ETH and laundered via Tornado Cash.