KuCoin Hack

The KuCoin hack was primarily a hot wallet key compromise rather than a smart contract exploit. While the exact details of how the private keys were obtained remain undisclosed, the attacker gained access to the private keys controlling KuCoin's hot wallets across multiple blockchains.

Once the keys were compromised, the attacker initiated a series of withdrawals:

1. The attacker gained access to the private keys for KuCoin's hot wallets
2. They systematically drained funds from these wallets to addresses they controlled
3. The stolen funds were transferred across multiple addresses in an attempt to launder them
4. Some assets were swapped on decentralized exchanges to make tracking more difficult

While not a smart contract vulnerability, the attack highlighted critical infrastructure security issues:

// Conceptual representation of the issue (not actual code)
class ExchangeWalletSystem {
  constructor() {
    // Vulnerability: Single point of failure in hot wallet key management
    this.hotWalletPrivateKeys = {
      "BTC": "privkey1...",
      "ETH": "privkey2...",
      "ERC20": "privkey3..."
    };
  }
  
  initiateWithdrawal(asset, amount, toAddress) {
    const privateKey = this.hotWalletPrivateKeys[asset];
    // Sign transaction with compromised key
    const signedTx = signTransaction(privateKey, toAddress, amount);
    return submitTransaction(signedTx);
  }
}