It gets even more fancy: the way Etherscan was tricked showing the wrong implementation contract is based on setting 2 different proxy slots in the same frontrunning tx. So Etherscan uses a certain heuristic that incorporates different storage slots to retrieve the implementation contract. There is an old proxy by OpenZeppelin who used the following slot: `keccak256("org.zeppelinos.proxy.implementation")` = `0x7050c9e0f4ca769c69bd3a8ef740bc37934f8e2c036e5a723fd8ee048ed3f8c3` We now also have the standard EIP-1967 slot `bytes32(uint256(keccak256('eip1967.proxy.implementation')) - 1)` = `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc` So what happened is that the old OpenZeppelin proxy slot was written to with the benign implementation address _and_ the standard EIP-1967 slot was also written to with the malicious implementation address. Since Etherscan queries first the old proxy slot, it retrieved the benign looking one first and thus displayed it.

- old OZ proxy slot: - old Etherscan blog on proxy support: - example frontrun tx: