Bybit: The $1.5 Billion Heist That Shook Crypto

On the afternoon of 21 February 2025, staff at Bybit sat down to approve what looked like a routine transfer. Bybit is a crypto exchange, a business that works like an online stockbroker: customers deposit money, trade digital coins and withdraw. The transfer was meant to move ether, the coin of the Ethereum network, from the exchange's deep storage to the account it uses to pay customers. Several senior people had to approve it, and they did. Within minutes about 401,000 ether, plus tens of thousands of related tokens, had gone to a wallet nobody at Bybit controlled.

The haul was worth about $1.46 billion, usually rounded to $1.5 billion. It remains the largest theft in the history of crypto, and by a distance: the next biggest, the 2022 raid on the Ronin bridge, took $625 million. It was also, on a single day, more than North Korea's hackers had stolen in the whole of 2024. Twenty months later, Bybit has got back about $48.4 million, and another $30.5 million is frozen. The rest has been washed through so many hands that Bybit itself says it can no longer follow most of it.

Bybit's chief executive and co-founder, Ben Zhou, confirmed the theft on X within about an hour and went on a livestream to say the exchange was solvent: every customer's money was still covered, because Bybit had enough of its own to fill the hole. Customers did not take his word for it, and billions of dollars of withdrawals followed over the next few days. Bybit kept paying them.

How a signature went to the wrong place

Exchanges hold customer coins in layers. Most sit in "cold" storage, kept offline like gold in a vault. A smaller amount sits in "warm" or "hot" wallets connected to the internet, the cash drawer at the bank counter. Moving money out of the vault needs a multi-signature approval, the digital version of a company cheque that three directors must all countersign.

Bybit's directors did not look at the raw blockchain instruction when they countersigned. Like thousands of crypto firms, they used Safe{Wallet}, a popular web app made by an outside company, which shows the signer a plain summary: from here, to there, this amount. The attackers never went near Bybit's keys. They went after Safe{Wallet}.

According to the forensic reports by the security firms Sygnia and Verichains, and Safe's own account, the attackers broke into a Safe{Wallet} developer's computer on 4 February 2025, apparently through social engineering, a trick that gets a person to open the door. From there they reached the company's cloud storage at Amazon Web Services and, on 19 February, planted a few lines of JavaScript, the code that runs inside a web page. The code did nothing for almost every user. It watched for one customer: Bybit's vault.

When Bybit's signers opened the app on 21 February, the screen showed the transfer they expected. The instruction their devices actually signed was different. It handed control of the vault to a program the attackers had written, which then emptied it. In stock market terms, the directors read a cheque made out to their own company, signed it, and the cheque the bank received was made out to someone else. Two minutes after the theft, the attackers swapped the clean code back in.

Who did it

On 26 February 2025 the FBI said publicly that North Korea was responsible, naming the operation it calls TraderTraitor, part of the wider state hacking network known as the Lazarus Group. The same network was blamed for the Ronin theft in 2022. Independent investigators had got there first: the blockchain sleuth ZachXBT and analytics firms including Elliptic and Arkham Intelligence tied the wallets to earlier North Korean thefts within hours. North Korea has never commented. The United Nations has long reported that the country's stolen crypto helps pay for its weapons programmes.

The analytics firm Chainalysis later counted $2.02 billion in crypto stolen by North Korean groups in 2025, most of it from Bybit, and about $6.75 billion over the past decade.

Where the money went

The laundering started within hours and was fast. The attackers split the ether across thousands of wallets and fed it through THORChain, a network that swaps one coin for another without asking who the customer is, turning ether into bitcoin. THORChain's validators, the operators who run it, voted not to block the flow, and one of its developers quit in protest. Some funds also went through eXch, a swap service that asked no questions. By 20 March 2025, Zhou reported that 86% of the stolen ether had been converted into about 12,800 bitcoin spread across more than 9,000 wallets. From there it went through mixers such as Wasabi, Railgun and Tornado Cash, services that pool many people's coins and pay out fresh ones, like a laundromat for money.

Each step made the trail fainter. In April 2025, Bybit's figures showed about 69% still traceable, 28% "gone dark" and under 4% frozen. By August 2026 Bybit was saying around 90% could no longer be traced.

What did come back came early. mETH Protocol, a service tied to the Mantle network, used an eight-hour withdrawal delay built into its own code to stop about 15,000 of its tokens, worth roughly $43 million, from leaving, and returned them. Tether and other firms froze smaller sums. Bybit offered 10% of anything recovered, up to $140 million, to whoever helped, and set up a public site, LazarusBounty, to track the wallets.

The courts

Governments moved later. In May 2025 Germany's federal police, the BKA, shut down eXch, seized its servers and took about 34 million euros ($38 million) in crypto, saying part of the Bybit money had passed through it. In July 2025 Greece's anti-money laundering authority froze a wallet on a Greek exchange that held part of the stolen funds, the country's first crypto seizure.

Bybit then sued the thieves. On 18 June 2026, under seal, it filed a civil case in the US District Court for the District of Columbia against North Korea, its military intelligence agency the Reconnaissance General Bureau, the Lazarus Group and 20 unnamed "John Doe" holders of the money. It uses the racketeering law RICO, the one US prosecutors use against organised crime, among others, and asks for the funds back plus about $1.5 billion in damages. The court granted a temporary restraining order the next day, and on 30 July 2026 a preliminary injunction, a court order barring the John Doe defendants from moving or selling the identified stolen assets while the case runs. Bybit made the suit public in August. A judgment against North Korea itself would be close to impossible to collect. The point is to make every exchange and custodian holding traced coins hand them over.

Bybit since

The exchange survived. Within about three days it had replaced the missing ether through loans from rivals and trading firms, big deposits and outright purchases. Bitget, a competitor, lent 40,000 ether, then worth about $100 million, with no interest and no collateral. An audit by the security firm Hacken, a proof of reserves that checks the exchange holds at least one coin for every coin owed, confirmed customers were fully covered. No customer lost money.

Since then Bybit has added more than 50 security changes and won licences in Europe, under the EU's MiCA rules, and in the United Arab Emirates. It now says it has more than 80 million users. The method has outlived the case: in September 2026, Bitget itself lost $387.5 million when attackers forged the instructions its own systems approved, and investigators again pointed to North Korea.