KiiChain

An attacker exploited chained balance-accounting defects in the shared Cosmos EVM module used by KiiChain. By deploying a contract at a precomputed vesting-account address and delegating one wei more KII than its spendable balance, the attacker triggered an arithmetic underflow in the staking precompile’s EVM balance write-back.

Combined with a missing overflow guard in the EVM value-transfer path, this allowed real KII to be redirected from victim accounts to attacker-controlled addresses without increasing total supply. The sequence was repeated against 18 targets.