A trading team's 2-of-7 Safe on Avalanche had granted unlimited WAVAX, USDC, WETH.e and BTC.b allowances in March to an address that hosted its pool contract on Base, Arbitrum and Ethereum, but was still empty on Avalanche. The approvals were never revoked.

That address was simply the 13th deployment output of Safe's public CreateCall contract, which had never been used on Avalanche. An attacker deployed CreateCall, ran 12 throwaway deployments, then placed a sweeper at the target address to pull every balance from the Safe.

An MEV bot copied the transaction and front-ran it in the same block, taking 3.09M USDC, 350.4K WAVAX, 182 WETH.e and 10.79 BTC.b, while the original attack reverted.

The bot claims to be a whitehat and is negotiating on-chain to return the funds for a 5 to 10% bounty. The same operator's signers have since moved Safes on HyperEVM, Base, Robinhood Chain, BSC and Ethereum into one fresh address now holding about $38.7M.