Ankr cross-chain bridge attack: all five forged receipts carried valid signatures

Odaily reports that according to SlowMist monitoring, the Ankr cross-chain bridge attack caused losses of approximately $304,500. The attacker referenced the same legitimate Optimism transaction, submitted five forged cross-chain receipts, and modified the recipient, token, and withdrawal amount. All five receipts carried valid signatures from trusted consensus signers of the cross-chain bridge, and the withdrawal function released assets without independently verifying the actual event on the source chain. The source of the unauthorized signatures is still under investigation, and it has not yet been confirmed that the signers were compromised.