According to Onchain Lens and Lookonchain, Bitcoin-focused DeFi protocol Echo suffered an exploit on Monday due to a compromised admin key affecting its Monad deployment. The attacker minted 1,000 eBTC (Echo's bitcoin liquidity token), deposited 45 eBTC to Curvance as collateral, and borrowed approximately 11.29 WBTC ($867,700), which was then bridged to Ethereum and swapped to ETH before being moved to Tornado Cash. Security researchers determined that ~$816,000 was stolen.
Echo announced early Tuesday that it regained control of the compromised keys and successfully burned the remaining 955 eBTC ($73.2 million) held by the attacker. Monad Co-founder Keone Hon confirmed the network itself was not affected. Curvance noted its isolated market architecture prevented contagion and paused the affected eBTC market as a precaution.