On March 23, the biggest crypto theft to date took place when crypto currencies worth roughly $625 million were stolen from the Ronin blockchain, that backs “Axie Infinity” a play-to-earn crypto game. A Thursday announcement from the Federal Bureau of Investigation (FBI) said that the hacking took place in North Korea. The crypto heist has been attributed to the Lazarus Group in the same country.

The agency also said that the Democratic People’s Republic of Korea’s (DPRK) Lazarus Group and APT38 were responsible for the theft that was reported on March 29th. The group was reportedly laundering the money for North Korea’s ruler Kim Jing Un. The federal law enforcement agency said that the US Treasury Department has been working to stem the flow of funds, by whatever means possible.

The Lazarus Group is the most notorious gang in North Korea. It is believed to be responsible for hacking over a billion dollars worth of crypto currency and cash. Hacking has become an abundant source of revenue in North Korea (DPRK) which has been facing sanctions from many countries around the world, from decades.

According to the Ronin Network, the hackers were able to access 173,600 ether and 25.5 million in USDC, which is a stable coin linked to the U.S. dollar.

The crypto is being laundered through Tornado Cash. This service lets people hide the place where the crypto comes from. Tornado Cash was also used by the hackers who had stolen $34 million, in January, from the website Crypto. It is still not known if the federal authorities are in the process of shutting down this service.

Ronin Network, owned by the developer group Sky Mavis, said that were “still in the process of adding additional security measures” and the bridge that was blocked off after the hacker attack, would be back by the end of the month. The bridge facilitated transfer of funds between Axie Infinity and other blockchain networks.