DeFi yield aggregator ACryptoS has ceased operations after a vault exploit drained approximately $665,000 across 77 vaults on five chains. The attack exploited a lack of input validation, allowing the hacker to mint the vast majority of vault shares by depositing minimal token amounts. The stolen funds have been moved through multiple cross-chain protocols. ACryptoS offered the attacker a 10% bounty for returning the assets and urged all users to withdraw their remaining funds immediately while withdrawals remain open.