It hacked Ronin, an Ethereum-based side network, best known for its connection to Axie Infinity.
More than $600 million in cryptocurrency was stolen as a result of the hack.
The "Sky Mavis" Twitter account revealed the incident, and stated that the hack had occurred since March 23, but it was only discovered earlier in the day, March 29.
According to the team, the hack involved the use of private keys which were used to forge the transaction.
According to the announcement, the hacker stole more than 173,000 WETH (encapsulated Ethereum) worth $597 million and about $26 million in USDC.
In all, the amount reached 622 million dollars in stolen cryptocurrency.
This hack is among the big hacks and ranks as high as the Poly network hack that had $600 million stolen from the network.
A look at the hacker's wallet shows that the money is still in his wallet.
According to the report, five out of nine audit signatures are needed to validate a deposit or withdrawal, but somehow, the attacker managed to control Sky Mavis's four Ronin authenticators and a third-party authenticator operated by Axie DAO.
The team revealed that it is working to mitigate future attacks by increasing the scrutiny threshold from five to eight.
It was also revealed that the team was already in contact with the security teams of the crypto exchanges to inform them when the funds were transferred to any of them.
According to Coingecko data, the AXS cryptocurrency has dropped in value rapidly.
The asset has lost more than 6% of its value in the last hour and is currently trading for $65.
Crypto community reaction:
Members of the crypto community reacted to the news of the hack and some wondered how the hack went on for nearly a week without anyone noticing.
Some of the feedback advised that transferring the original cryptocurrency from one chain to another is the right way.
Other members of the community wondered if the hacker would return the loot or if the team would return the money to the affected users.
