Hackers have stolen some $600m (£433 million) in what could be the largest cryptocurrency heist to date.
Blockchain site Poly Network said hackers exploited a vulnerability in its system, taking thousands of digital tokens such as Ether.
About $267m of Ether currency was taken, $252m of Binance coins and roughly $85 million in USDC tokens.
In an open letter posted on Twitter, the company asked the hackers to initiate a conversation and return their stolen assets.
Within hours of the hack, the attacker started returning the funds to Poly – first in small amounts and then by making much larger deposits, totalling hundreds of millions of dollars.
The recent hack is on par with huge breaches at exchanges such as Coincheck and Mt. Gox.
In its letter Poly Network said: “The amount of money you have hacked is one of the biggest in defi decentralised finance history.
“Law enforcement in any country will regard this as a major economic crime and you will be pursued”.
“The money you stole are from tens of thousands of crypto community members, hence the people”.
Poly Network said a preliminary investigation found the hacker had exploited a “vulnerability between contract calls”.
After millions of dollars in tokens were transferred to separate cryptocurrency wallets, It urged various exchanges to block deposits of the coins.
Changpeng Zhao, chief executive of Binance, said his firm was aware of the hack, but added there was only so much he could do.
He said the group was “co-ordinating with all our security partners to proactively help”.
“There are no guarantees,” he added.
Poly Network is a decentralised finance service provider that allows users to transfer tokens from one blockchain network to another.
The Poly token supports interoperability between networks, allowing people and entities with different crypto holdings the ability to easily transact.
