Hackers return $260 million to crypto platform

Poly Network, a decentralised finance platform that facilitates peer-to-peer transactions, said on Twitter that $260 million of the stolen funds had been returned but that $353 million was outstanding.

The company, which allows users to swap tokens across different blockchains, said on Tuesday it had been hacked and urged the culprits to return the stolen funds, threatening legal action.

The hackers exploited a vulnerability in the digital contracts Poly Network uses to move assets between different blockchains.

A person claiming to have perpetrated the hack said they did it "for fun" and wanted to "expose the vulnerability" before others could exploit it, according to digital messages shared on the internet.

It was "always the plan" to return the tokens, the purported hacker wrote, adding: "I am not very interested in money."

The hackers or hacker have not been identified, and the authenticity of the messages could not be verified.

The size of the theft was comparable to the $530 million in digital coins stolen from Tokyo-based exchange Coincheck in 2018.

The Poly Network attack comes as losses from theft, hacks and fraud related to decentralised finance (DeFi) hit an all-time high.

At $600 million, however, the Poly Network theft far outstripped the $474 million in criminal losses that were registered by the entire DeFi sector from January to July.

The thefts illustrated risks of the mostly unregulated sector and may attract the attention of regulators.

The sector has boomed over the last year, with platforms now handling more than $80 billion worth of digital coins.