Worked example · 2026-10

Unnamed trading Safe — unlimited approvals to an address that held the team's pool on other chains but was empty on Avalanche, so anyone could deploy there — Safe multisig / Avalanche — 2026-10-26

Loss

~$7.45M (3.09M USDC, 350.4K WAVAX, 182 WETH.e, 10.79 BTC.b) taken from a 2-of-7 Safe holding trading inventory. An MEV bot front-ran the original attacker in the same block, took the funds, called itself a whitehat and offered to return them for a 5–10% bounty. The operator evacuated its Safes on five other chains (~$38.7M) to a fresh address.

OAK Techniques observed

OAK-T9.004 (Access-Control Misconfiguration — primary. On 2026-03-07 the Safe approved unlimited WAVAX, USDC, WETH.e and BTC.b to 0x3725bd4d175283108156c3f15f86e1c51266155d. On Base, Arbitrum and Ethereum the team's pool lives there; on Avalanche the address was empty, and it is simply what Safe's public CreateCall contract produces on its 13th deployment. An attacker deployed CreateCall via the Safe singleton factory, ran 12 throwaway deployments, then put a sweeper at that address. See techniques/T9.004-access-control-misconfiguration.md). No signer key was compromised.

Attribution

pseudonymous; the operator is not publicly named.

Key teaching point

The same address is not the same contract on another chain. Approving a counterfactual address on a chain where nothing is deployed hands the allowance to whoever deploys there first. Check code at the spender before approving, per chain, and revoke allowances that nothing uses.