Echo Protocol has experienced a security breach on the Monad chain, resulting in the unauthorized minting of 1,000 eBTC. The attacker used part of the minted eBTC as collateral to borrow assets and executed cross-chain transfers, affecting approximately $8.16 million. On-chain security firm PeckShield reported that the attacker minted around $76.7 million worth of eBTC, depositing 45 eBTC into Curvance and borrowing 11.29 WBTC, which were converted to ETH and partially sent to Tornado Cash. The Echo Protocol team confirmed that the breach was due to compromised administrative keys affecting Monad's deployment, though the Monad network itself remains operational. The team has regained control of the management keys and destroyed the remaining 955 eBTC held by the attacker. Cross-chain functionality has been suspended as a precaution, and the team is upgrading their EVM series bridge deployment to enhance security. The incident underscores the risks associated with DeFi protocols' reliance on centralized key management and off-chain infrastructure.