Binance executives are racing to cover billions in losses from the biggest crypto heist in history, a breach that blew past everything the exchange had set aside to cover such an incident. The hackers plundered $6.3 billion from the exchange’s digital wallets by breaking into a Binance engineer’s laptop, among other breaches, Binance said. Stablecoin issuers Tether and Circle, along with other crypto firms, managed to freeze about $3 billion of that sum, leaving roughly $3.3 billion under the hackers’ control. Binance has an emergency reserve called the Secure Asset Fund for Users, or SAFU, set up for cyber incidents…