Cosine: Bybit attacker uses three owners to sign a transaction that replaces the Safe implementation contract with a malicious contract

PANews reported on February 22 that SlowMist Cosine disclosed some details of the Bybit Safe multi-signature hack on the X platform: The malicious implementation contract was deployed at 0xbDd077f651EBe7f7b3cE16fe5F2b025BE2969516 at UTC 2025-02-19 7:15:23

The attacker used three owners to sign the transaction 0x46deef0f52e3a983b67abf4714448a41dd7ffd6d32d32da69d62081c68ad7882 to replace the Safe implementation contract with the malicious contract at UTC 2025-02-21 14:13:35

Malicious upgrade logic is embedded into STORAGE[0x0] 0x96221423681A6d52E184D440a8eFCEbB105C7242 via DELEGATECALL

The attacker then used the backdoor functions sweepETH and sweepERC20 in the malicious contract to withdraw assets from the hot wallet.