Vietnamese blockchain game developer Sky Mavis created the Ronin Network to serve as a sidechain for the company’s Axie Infinity game. The tool is used by gamers to transfer virtual coins in and out of the game. However, it has been revealed that hackers were able to break into the Ethereum sidechain and steal millions of dollars’ of cryptocurrency from it. Sky Mavis only discovered the cyberattack after a user complained yesterday that they were unable to withdraw funds from the network. However, Sky Mavis discovered that that the cyber incident occurred a week ago.

According to the game developer, an attacker compromised the Ronin and Axie DAO validator nodes, using hijacked private keys to forge fraudulent withdrawals. In only two transactions, the attacker was able to steal $592 million in Ethereum and $25.5 from the Ronin bridge. In all, the Ronin chain consists of only nine validator notes. In order to recognize a deposit event of withdrawal event, five out of the nine nodes are typically needed. However, the attacker was able to gain control to four Ronin validators and a third-party validator under Axie DAO. Ronin Networks is still working on mitigating the effects of this attack, and has paused its bridge functionality until resolved.

Read More: Attackers Steal $618m From Crypto Firm