Binance narrows down identification of hacker behind BNB crypto hack: CEO

Cryptocurrency exchange Binance is closing in on the identity of a hacker who orchestrated a $570 million hack on its BNB blockchain, CEO Changpeng Zhao told CNBC on Monday.

After receiving some leads from law enforcement as to who the hacker might be, Binance is now “narrowing down” the person or persons behind the attack, Zhao said in an interview on CNBC’s Squawk Box Europe.

The attack in question involved a so-called cross-chain bridge that allowed one or more as-yet-unknown hackers to withdraw 2 million BNB tokens from Binance, worth around $570 million at the time.

According to Chainalysis data, more than $1 billion has been lost so far this year to breaches on cross-chain bridges, tools that facilitate the rapid transfer of tokens from one blockchain platform to another.

Bridges, popular in the world of “DeFi” or decentralized finance, have become a hot target for criminals due to flaws in their underlying code.

“We’re still hunting…helping [authorities] to hunt down the bad players and cooperate with law enforcement agencies around the world,” Zhao said. “Working with law enforcement is one of the ways we can try to make space safe.”

“Actually, at this particular moment, law enforcement gave us some tips on who they think it could be. So we are actually narrowing ourselves down.”

Binance intervened to limit the damage from the attack, halting activity on its BNB Chain blockchain network after coordinating with network validators — individuals and organizations that sign transaction permits — to issue an upgrade.

Zhao, commonly referred to as “CZ” on the internet, said it means the BNB chain can prevent most of the targeted funds from being stolen by the hacker.

“The blockchain was able to freeze about 80% to 90% of that, so the actual loss was much less,” he said.

The “vast majority of funds remain under control,” Binance’s BNB chain said in a statement at the time of the hack. About $100 million is non-refundable, BNB Chain added.

The BNB chain, originally known as Binance Chain, was first developed by Binance in 2019. Like other blockchains, it has a native token called BNB that can be traded or used in games and other applications.