On October 29, Binance lost control of about $6.34 billion in digital assets in a matter of hours. The attackers did not break in on that day, though. They had been working their way inside since June. The Binance hack was a slow campaign aimed at a handful of engineers, and it used a tampered download, a fake job interview and the exchange’s own internal AI tool to reach the systems that sign transactions.
Binance CEO Richard Teng called it “one of the most sophisticated attacks the digital asset industry has ever seen.” He said the company takes full responsibility and that no user will bear the loss.
Why the Binance Hack Targeted Engineers, Not Systems
According to the post-mortem Binance released on Tuesday, the attackers went after people with access to wallet infrastructure.
In June, Wallet DevOps Engineer A searched for a popular AI coding tool and downloaded a tampered Homebrew installation. Binance’s security team spotted the anomaly, replaced the device and rotated his credentials. But the damage was done in another way: Engineer A’s role, and his colleagues on the wallet infrastructure team, were now known to the attacker.
In September, the attackers moved to social engineering. Software Engineer B, whose profile on a legitimate job-hunting platform mentioned his Binance experience, was approached by someone posing as a project director. A first-round video interview followed with a supposed HR representative, who shared personal photos and videos on social media to build trust. Binance said this was more advanced than social engineering it had seen before.
In the second round, held on a popular chat app, Engineer B was told to download an “assignment” onto his work computer. It contained malicious code that ran during setup, swapped a legitimate development tool for a malicious version, and connected to an attacker-controlled server. The zero-day malware was not detected by endpoint security tools at the time.
On October 20, the attackers used Engineer B’s compromised computer and an internal AI tool to gain control over Engineer A and another wallet engineer, Engineer C. They then found that Engineer A had a container deployment permission token on his machine.
How the Binance Hack Unfolded on October 29
Between 17:15 and 19:56 UTC, the attacker logged onto Engineer C’s computer, used Engineer A’s stolen credentials, deployed a container and triggered a malicious script. That gave them unauthorized access to an internal wallet signing service, which they used to send transactions outside the normal withdrawal process.
Between 20:05 and 20:09 UTC, five Binance hot wallets sent 233.46 million XRP to an attacker-controlled address. Hot wallets on Solana and Optimism sent about 970,500 SOL and 44.2 million OP. Binance then received an internal alert about large transfers, and another hot wallet sent 18,270 BTC.
Why Binance Couldn’t Stop It Faster
Binance suspended withdrawals, but that did not end the outflows. The attacker had used the signing service to exploit Ethereum’s EIP-7702 authorization mechanism. By submitting 50 signing transactions, they gave an attacker-controlled smart contract partial execution rights over a Binance hot wallet.
Those authorizations lived on-chain and worked independently of Binance’s withdrawal systems. And because the wallet used Multi-Party Computation, there was no single private key that could instantly revoke them. Binance had to build a special procedure to do it. The final unauthorized transfer of 2,961.9 ETH was confirmed at 23:56 UTC. At 00:10 UTC on October 30, Binance cleared the malicious delegation.
Who Is Behind It
Over the weekend, the FBI and other U.S. agencies blamed the theft on TraderTraitor, a North Korea state-sponsored group that has spent years attacking cryptocurrency platforms. Binance said it had detected and stopped 57 suspected North Korea-linked threats in 2026 alone, many using fake job interviews and malicious developer tools.
On Tuesday, Kim Yo-jong rejected the U.S. findings, calling them a “grave political provocation” in a statement carried by the Korean Central News Agency. Observers noted the statement ended by saying Pyongyang had matters to “reconsider,” without directly threatening retaliation.
South Korea’s Unification Ministry called her personal response unprecedented. An official said it suggested the North was taking the allegations seriously and was “increasingly conscious of its international standing.”
Where Users Stand
Binance says it has set aside more than 100% of the funds needed to cover the loss. As of October 31, 98% of impacted token assets had been replenished, and Binance is buying the remaining, less liquid assets. About $2.85 billion has been frozen or intercepted with help from law enforcement, token issuers and blockchain intelligence firms. Withdrawals have broadly resumed.
The exchange says it has rebuilt the affected wallet system and AI tool, replaced devices, revoked credentials tied to the affected engineers and brought in independent security firms.
The investigation is ongoing.
