Like a thief getting onto a bank teller’s computer.
The internal system that approves and sends customer withdrawals.
Each must match a reference number that changes with every transaction. Only one has to work.
The till is emptied, but the vault (cold storage) stays shut.
New customer deposits flow in, and the attacker takes those too.
Around US$3 billion is frozen by stablecoin issuers, and Binance covers the remaining losses from its own reserves.