SlowMist: All five forged receipts in the Ankr cross-chain bridge attack carried valid signatures

TechFlow reported that on November 9, based on SlowMist monitoring, an attack on the Ankr cross-chain bridge resulted in approximately $304,500 in losses. The attacker cited the same valid Optimism transaction to submit five forged cross-chain receipts, modifying the recipient, tokens, and withdrawal amounts.

SlowMist stated that all five receipts carried valid signatures from the cross-chain bridge's trusted consensus signers, allowing the withdrawal function to release assets without independently verifying actual events on the source chain. The unauthorized signing source remains under investigation, and it has not yet been confirmed whether the signers were compromised.