Cryptocurrency worth more than $6.3bn (£4.7bn) has been stolen from a major exchange - with one industry insider telling Sky News it is "the largest bank heist in human history".

The security exploit targeted Binance, one of the world's biggest platforms for trading digital assets, which said it is establishing the facts with urgency.

Deposits and withdrawals have been suspended for customers - with the company insisting that user funds are safe, and all hacking losses will be covered.

According to TRM Labs, a blockchain intelligence firm that tracks the industry, an elite North Korean hacking unit called TraderTraitor was responsible for the theft - and it was completed in just 20 minutes.

That would make it the largest cryptocurrency hack to date - surpassing the $1.5bn that was stolen when the Bybit exchange was targeted last year.

Ari Redbord, chief policy officer of the crypto analytics company TRM Labs, told Sky News: "This is an extraordinary hack, for its size and for the response ... Few financial systems have ever shown a theft of this scale."

He explained the attacker was able to move billions of dollars across eight blockchain networks in about 15 minutes - and the TraderTraitor group has also been linked to the Bybit hack by the FBI.

It is believed the hacker responsible was preparing for at least 36 hours before the theft took place.

"The theft shows how exposed the system is to sophisticated attackers moving at a speed we have never seen," he added.

After Binance's security issue was identified, digital assets worth more than $3bn (£2.2bn) were frozen, which could prevent the funds being cashed out by malicious actors.

But Mr Redbord said the attacker still controls about $2.4bn (£1.8bn) worth of Bitcoin and Ether - the two biggest cryptocurrencies by valuation.

Izabella Kaminska - who edits independent publication The Blind Spot and reports on the crypto industry - told Sky News it "appears to be a highly sophisticated and well-rehearsed attack".

She said the hack comes at a time of growing concern that major cyber vulnerabilities in the financial system are about to be exposed or exploited by AI agents.

Ms Kaminska explained that the crypto industry has long sought to differentiate itself from the banking sector by claiming it is decentralised and resistant to censorship.

However, the former Financial Times journalist added: "The reality is and always was that the vast majority of crypto platforms - and in some cases assets too - are just as structurally centralised as conventional banking platforms.

"Unlike banks, however, when these systems get hacked or become insolvent, there is no recourse to a lender of last resort or deposit insurance fund. Depositors are on their own."

On X, Binance said its security team is "reviewing all relevant information with urgency" - and urged its users to remain cautious of scams.

The company claims it has more than 335 million users around the world.

Bitcoin, the world's biggest cryptocurrency, dropped sharply in response to the news.

As of 1am UK time on Friday, it was trading at about $77,000 (£57,500) - falling by 5% over the past 24 hours. Some smaller digital assets have seen their values plummet by closer to 10%.

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"While that is a significant drop, it is far from unprecedented for an asset class which is used to very sharp moves," Ms Kaminska added.

Although it is too early to determine if this hack is an existential threat to the crypto industry, she warned the bigger question is whether this could cause trouble for the wider financial system - with closer ties formed between the digital assets space and Wall Street in recent years.

"The crossover contagion risk is no longer zero," she said.

Asymmetric Research chief executive Jonathan Claudius told Sky News that "the preparations and techniques" for this attack are consistent with those used by North Korean hacking groups.

Crypto Watchdog's executive director, Chapin Fay, warned freezing assets does not guarantee stolen funds will be recovered.

"The reported attack highlights the vulnerabilities of even the largest crypto exchanges," he told Sky News. "Customers deserve safeguards across the services handling their money, alongside clear answers about how any losses will be covered."

Chainalysis head of research Eric Jardine said industry-wide coordination is helping disrupt the movement of stolen funds.

He added: "Crypto exchanges are particularly attractive targets for hackers, regardless of where they are based, because - to borrow a line often attributed to bank robber Willie Sutton - 'that's where the money is'.

"While the scale of this incident is significant, attacks on exchanges are not new. Every exchange should remain vigilant."

(c) Sky News 2026: Crypto industry suffers 'largest bank heist in human history' as billions stolen in Binance hack