The hacker who stole around $610 million worth of cryptocurrency from Poly Network earlier this month has returned the final slice of stolen funds to the firm.
The platform confirmed that it had successfully retrieved all but $33 million.
‘As of now, Poly Network has regained control of the $610 million (not including the frozen $33 million USDT) in assets that were overall affected in this attack. Once again, we would like to thank Mr. White Hat [the hacker’s name for themselves] for keeping his promise, as well as the community, partners and the multiple security agencies for their assistance,’ the firm said.
The cryptocurrency heist – believed to be the biggest of all time – took place earlier this month, when a hacker broke into decentralised finance (DeFi) platform Poly Network and stole more than $600 million worth of various cryptocurrencies.
The attacker claimed that a security flaw in Poly Network’s system enabled them to transfer the money to another account. They said their aim was to expose the security vulnerability before it was exploited by “an insider”.
“The Poly Network is a decent system. It’s one of the most challenging attacks that a hacker can enjoy. I had to be quick to beat any insiders or hackers.”
After identifying the attack, the platform urged crypto exchanges to block the funds that were taken. It also requested the hacker to return the stolen funds.
In a strange twist of events, the hacker actually did do that – opening a dialogue with Poly Network, rather than running off with their proceeds.
By 11th August, the hacker had sent back $256 million on Binance Smart Chain, $3.3 million in Ethereum and $1 million in Polygon – although there was still $269 million in Ethereum and $84 million in Polygon missing.
The company asked the hacker to return the remaining funds and also promised to grant them a $500,000 bounty for helping it uncover a security vulnerability in its systems.
Poly Network even offered the hacker to act as the company’s chief security advisor.
‘To extend our thanks and encourage Mr. White Hat to continue contributing to security advancement in the blockchain world together with Poly Network, we cordially invite Mr. White Hat to be the Chief Security Advisor of Poly Network,’ the firm said in a statement.
Poly said it had ‘no intention of holding Mr. White Hat legally responsible’ for the hack.
In its blog post on Monday, the company said that while the hacker had returned most of the stolen money, more than $200 million of assets was locked in an account that required private keys from both the firm and the hacker to gain access.
For some time, ‘Mr. White Hat’ refused to hand over their private keys, but finally decided to share the keys to enable the platform to regain control of the remaining assets: 28,953 Etherium and 1,032 Wrapped Bitcoin, worth roughly $141 million.
Poly Network has now entered the fourth phase of its ‘Asset Recovery’ roadmap and is working to return ‘full asset control to users as swiftly as possible’.
‘Once all assets have been successfully restored, Poly Network will gradually resume cross-chain functionality for all the assets, along with other functions, subject to full security confirmation,’ it added.