One of the 12 largest DeFi, Crypto hacks. My summary here: https://crypto.security/crypto-blockchain-security/poly-network-hack/
The Poly Network is a DeFi platform that enhances blockchain interoperability by enabling users to transfer information and cryptocurrencies between various blockchains.
Through a series of data manipulation techniques in the high-level code of the Ethereum smart contract, the attacker was able to grant himself the necessary permissions to transfer all Poly Network funds on the Ethereum blockchain into his own wallet, which included 2,528 ETH valued at $267M at the time.
The same method was used to extract 6,610 BNB valued at $252M to the attacker’s BNB Smart Chain wallet, and again it was used to transfer roughly $85M worth of USDC into the attacker’s wallet on the Polygon network.
The stolen assets also included several million dollars worth of Shiba Inu, DAI, USDT, and BUSD, for a grand total of around $611M at the time of the attack and making it the biggest crypto hack as of October 2022.
A comprehensive technical report by Kraken Security Labs is here: https://blog.kraken.com/post/11078/abusing-smart-contracts-to-steal-600-million-how-the-poly-network-hack-actually-happened/
