Hackers stole cryptocurrency worth roughly $625 million from Ronin, the blockchain behind the popular crypto game Axie Infinity.
Axie Infinity and Ronin Network operator Sky Mavis revealed the breach in a blog post on Ronin Network’s official Substack. The operator froze transactions on the Ronin Bridge, which allows withdrawing and depositing funds from the company’s blockchain.
Sky Mavis said its working with the police to recover the stolen 173,600 Ethereum (ETH), which is currently worth nearly $600 million, and 25.5 million USDC, a cryptocurrency pegged to the U.S. dollar, from the hacker who stole it from the Ronin network on March 23rd.
The cyberattack was focused on the bridge to Sky Mavis’ Ronin blockchain, an intermediary between the NFT-based game Axie Infinity and other cryptocurrency blockchains such as Ethereum. Users could deposit either Ethereum or USDC to Ronin, buy NFTs or in-game currency, or sell their in-game assets and withdraw the money.
According to the operator, Sky Mavis, the hacker used compromised private security keys to enter the network nodes that validate the transfers on the Ronin blockchain, which enabled the attacker to withdraw massive amounts of Ethereum (ETH) and USDC. The hack was discovered nearly a week later when another user attempted to withdraw 5,000 ETH via the bridge.
Analysts suspect this to be the largest crypto hack ever.