How a simple coding mistake let a hacker drain $7.8 million from a crypto wallet

An attacker was able to extract roughly $7.8 million from a cryptocurrency wallet after exploiting a simple coding error in a helper smart contract that had been given permission to act on the wallet's behalf. The drain prompted an investigation by security firms that examined where the failure occurred.

Those investigators determined the root cause was the third-party helper contract the wallet owner had authorized. According to their analysis, the wallet software Safe was not the source of the vulnerability; instead, the authorized auxiliary contract contained the coding mistake the attacker exploited.

Because the contract had been explicitly permitted by the wallet owner, the incident emphasizes the risk introduced whenever users grant external contracts authority to interact with their wallets. Even when core wallet software is secure, poorly written or insufficiently audited helper contracts can create an attack vector.

The episode underlines the importance of carefully reviewing and vetting any third-party contracts and approvals granted from a wallet, and shows the role of security investigations in clarifying whether a breach stems from platform-level flaws or from user-authorized components.