Biggest Hack in Crypto History: What You Need to Know

• The Binance breach is the biggest hack in crypto history, and TRM Labs links it to North Korea.
• One valid EIP-7702 authorization gave the attacker control of a major Binance hot wallet.
• The malicious delegation stayed active and drained new deposits without another signature.
• Binance is covering losses from company funds while issuers freeze stolen stablecoins.

The biggest hack in crypto history hit Binance on October 29, when an attacker drained roughly $6.3 billion from the exchange’s wallets on ten blockchains, most of it within about 20 minutes. Blockchain intelligence firm TRM Labs puts the total at $6.36 billion, around four times the $1.5 billion stolen from Bybit in February 2025. It attributes the attack with high confidence to TraderTraitor, a North Korean state hacking unit. Binance has pledged to cover all confirmed losses, and while deposits are running normally again, withdrawals remain paused and are expected to restart in about 45 hours. Its preliminary investigation first pointed to a compromised DevOps engineer’s laptop that gave the attacker access to a service container used to submit unauthorized withdrawals. Binance has since said investigators found additional breach points.

Tornado Cash Trail Leads to TraderTraitor

The attribution in TRM Labs’ analysis of the attack rests on habits the group has shown before. Starting on the morning of October 28, the operator wallet received three small withdrawals from Tornado Cash, a mixer that hides where funds come from. Early on October 29 the attacker tested the code on two wallets and then ran a final rehearsal on a third. The Bybit theft, which the FBI attributed to TraderTraitor, followed the same method of collecting signatures in advance and firing them in one burst.

The laundering went a different way. Bybit’s attackers relied mainly on bridges, but this attacker sold about 325 million USDT through UniswapX for roughly 122,300 ETH. That implies a price near $2,650 per ETH while the market sat around $2,300, so the attacker overpaid by more than 10% to get out of stablecoins before issuers could freeze them. A separate wallet deposited 60 million USDT on Aave and borrowed about 19,760 ETH against it before Aave froze the affected markets. On Tron, 300 million USDT went into the lending protocol JustLend.

49 Failed Signatures, One Open Wallet

EIP-7702 went live with Ethereum’s Pectra upgrade in May 2025. It lets an ordinary wallet hand its execution to a smart contract, a feature designed for batched transactions and gas sponsorship. Each authorization has to match the wallet’s nonce, the running count of transactions it has sent. Binance’s hot wallet labelled Binance 14 was processing withdrawals too quickly for that number to be predicted.

To get around this, the attacker sent a single transaction at 20:20:59 UTC carrying 50 authorizations, one for each nonce from 18,914,775 to 18,914,824. Forty-nine failed. The one that matched pointed Binance 14 at an unverified sweeper contract, and about three minutes later that contract moved 167,464 ETH, 1.615 billion USDT and 63 other tokens, worth roughly $2.5 billion, in one transaction. Only an address designated by the attacker could call the contract’s sweep function, which left 1 ETH in the wallet to pay for gas.

Blockaid CEO Ido Ben-Natan calls this misuse of Binance’s keys rather than theft of them, because the attacker most likely already had access to the systems that sign Binance’s transactions. EIP-7702 allowed dozens of assets to leave in one operation, which left withdrawal monitoring with fewer separate transfers to intercept. TRM’s data supports that reading: on the other nine chains, Binance wallets sent funds through ordinary signed transfers with no delegation involved. Binance has not disclosed which of its checks failed.

A Second Sweep With No New Signature

Blockaid’s incident report shows that the delegation stayed active after the first drain. At 20:41 UTC the attacker used Binance 14 to reach a Circle smart account owned by Binance and pulled about $780 million in USDC, followed by another $43 million. Together that roughly matches the 823 million USDC that Circle froze at 21:04 UTC in coordination with law enforcement. At 21:44 UTC the attacker returned and swept more than $200 million in fresh deposits from Binance 14 without any new signature.

Rotating keys does not undo an EIP-7702 delegation. It stays active until someone explicitly revokes or replaces it, so a brief compromise of signing systems can leave the attacker with lasting control over an address. Binance co-CEO Richard Teng said the affected authorizations have since been revoked.

From XRP at 20:05 to Arbitrum at 00:08

Ethereum was only one part of a coordinated operation. It began at 20:05 UTC, when five Binance wallets on the XRP Ledger sent 233.46 million XRP to a single attacker address. A Bitcoin hot wallet released 18,270 BTC in the same minute the Ethereum authorizations went in, and a Tron hot wallet sent 612.7 million USDT within two minutes of that. A second wave hit Binance wallets on Avalanche and Polygon at 23:05 UTC, nearly three hours after the first transfers.

$6.34B Reserve vs. CZ’s $2B Gap

Binance says it has reserved more than $6.34 billion of company funds, $5 billion of which is already held in the exact tokens that were stolen. It is buying the rest on exchanges and through over-the-counter (OTC) desks, which arrange large private trades, and has warned that this could be slow for thinly traded tokens. Binance founder Changpeng Zhao (CZ) gave a rougher calculation on X after Tesla and SpaceX CEO Elon Musk responded to the news with a grimacing emoji. CZ counted $6.x billion hacked, $3 billion frozen and $1.x billion in SAFU, the Secure Asset Fund for Users that Binance set up in 2018, which leaves a gap of about $2 billion. He added that Binance holds $1.x billion in SPCX shares from its $500 million investment in Musk’s Twitter takeover and called the remaining shortfall “still painful, but manageable.”

@elonmusk @HuaweiMate6 Elon, have a lot of respect for you, but bad time to troll. Please stop.

Our SPCX shares (from our $500m investment in your Twitter takeover) are worth more than a billion.

Would appreciate if you show a little support. Thanks!

— CZ BNB (@cz_binance) October 30, 2026

CZ’s calculation assumes the frozen funds come back. TRM counts about $2.7 billion frozen so far, led by roughly $1.77 billion in USDT frozen by Tether and $825 million in USDC frozen by Circle. Ripple froze 40.5 million RLUSD and World Liberty Financial froze 27.8 million USD1, while the Arbitrum Security Council moved 8,426 ETH and 74.6 million ARB out of the attacker’s reach early on October 30. As of early October 30, the attacker still held more than 420,000 ETH and 18,270 BTC, worth about $2.4 billion, which no issuer can freeze. Bitcoin fell more than 4% after the news and was trading around $77,000 at the time of writing.

Key Rotation No Longer Ends an Attack

Exchanges will now need to monitor their Ethereum hot wallets for delegated code as well as outgoing transfers, and treat any delegation request coming from an exchange wallet with the same caution as a request to export a private key. Response playbooks that end with rotating keys need an added step to revoke delegations, because deposits arriving at a delegated address stay exposed until that happens. Blockaid says its systems flagged the drain less than two minutes after the first sweep and confirmed the delegation mechanism within 11 minutes, before any public report, which shows what real-time monitoring can catch. TRM expects the remaining ETH and BTC to move through bridges, swap services and OTC brokers, so those desks will face pressure to screen unusually large incoming flows.

Blockaid saw this risk coming at a much smaller scale. In the first half of 2026 it verified four EIP-7702 incidents worth about $1.08 million combined, and its mid-year report predicted the first seven-figure case before the end of the year. Binance has promised a technical post-mortem once its investigation is complete. That report will need to explain how the attacker obtained valid signatures for wallets on ten chains within roughly half an hour.