Binance CSO says halting withdrawals alone couldn’t have stopped $6.3B hack outflows

Binance Chief Security Officer Jimmy Su said during an ongoing AMA on X that the transaction-approval vulnerability exploited in the Oct. 29 hack existed on-chain and did not pass through Binance’s withdrawal system, so suspending withdrawals alone could not have prevented the outflow of funds. Su explained that revoking the attackers’ transaction approvals required a new on-chain transaction, and setting up a separate cancellation process took considerable time because Binance hot wallets use multi-party computation, or MPC, technology and the approvals could not be immediately revoked with a single private key. Su added that Binance has hired external security experts to conduct an independent, comprehensive review of the hack, verify the results of its internal investigation and propose improvements. Binance is also working with major AI companies and security firms on plans to establish a security research fund focused on blockchain- and AI-related threats.