Hackers have stolen about $6.3 billion worth of digital assets from Binance, a major cryptocurrency exchange operator.

The heist is more than four times bigger than the previous largest crypto theft. TRM Labs Inc., a venture-backed blockchain intelligence startup, believes that both cyberattacks were carried out by a North Korean state-backed hacking group tracked as TraderTraitor.

About 40% of the stolen sum comprised stablecoins issued by three major crypto companies: Circle Internet Group Inc., Ripple Labs Inc. and Tether Ltd. They managed to freeze most of the funds before the hackers moved them out of reach. Binance, for its part, has set aside over $6.34 billion to cover users’ losses.

The hackers stole the funds by compromising…