A crypto hacker just pulled off one of the largest heists in history, swiping $625 million in tokens

• An attacker stole $625 million in tokens from Ronin Network last week, it said Tuesday.
• "The attacker used hacked private keys in order to forge fake withdrawals," Ronin Network said in a blog post.

A crypto hacker targeted Axie Infinity's Ronin Network and made away with $625 million worth of ether and stablecoin USDC.

The Ronin Network published a blog post Tuesday explaining how its network was exploited for 173,600 ether and 25.5 million USDC, and that it impacted the Ronin Network validator nodes for Sky Mavis.

It said it has since halted transactions on its Ronin Bridge and Katana Dex servers.

"We are working with law enforcement officials, forensic cryptographers, and our investors to make sure all funds are recovered or reimbursed," Ronin Network wrote. "The attacker used hacked private keys in order to forge fake withdrawals."

The blog post noted that the attacker entered through a "backdoor" of one of Ronin's nodes, and that Etherscan records reveal that the attack took place last Wednesday.

Most of the stolen funds remain in the attacker's address, but about 6,250 ether has been transferred to a slate of other addresses.

Last August, crypto hackers stole over $600 million from cross-chain protocol, Poly Network, though most of the stolen funds were eventually returned.

The native token of the Ronin network, RON, is down more about 22% on the news.