A leading cryptocurrency exchange has reported that it fell prey to a sophisticated cyberattack, resulting in the theft of approximately $1.5 billion in digital assets—an incident that ranks among the most significant online heists in history.

Bybit announced on Friday that a routine transaction involving Ethereum—a widely-used cryptocurrency—was “manipulated” by an unauthorized individual who redirected the assets to an unknown wallet address.

The company has assured its customers that their funds held on the platform remain secure. However, they noted that the breach has led to an uptick in withdrawal requests, which may result in processing delays.

Ben Zhou, the CEO of Bybit, stated on social media that the company can maintain its financial health even in the event that the stolen cryptocurrencies are not retrieved.

“We can absorb the loss,” he declared.

Cybercriminals frequently target cryptocurrencies as part of their operations. In particular, North Korean state-sponsored hackers have been implicated in multiple high-value crypto thefts over the past few years.

In December, the FBI, in collaboration with the Department of Defense and the National Police Agency of Japan, released a joint statement attributing a theft of $308 million from a Japanese cryptocurrency firm to North Korean hackers.