Hackers stole roughly $41 million worth of cryptocurrencies from Stake.com, an online casino and sports betting site, this week. On Wednesday, the FBI attributed the hack to North Korea and its infamous state-sponsored Lazarus Group.

“The FBI has confirmed that this theft took place on or about September 4, 2023, and attributes it to the Lazarus Group (also known as APT38) which is comprised of DPRK cyber actors,” the agency said in a press release.

Stake.com co-founder Edward Craven told crypto news outlet DL News that the attack was a “sophisticated breach” that exploited a service that the casino uses to authorize crypto transactions. Regardless of the eye-popping sum that was stolen by the government hackers—especially as crypto prices remain stuck in a serious slump—Craven said that Stake.com would continue to operate.

North Korea’s Lazarus Group is notorious and was added to the U.S. sanctions list in 2019. The group, also known as APT38, is responsible for numerous high-profile hacks that have occurred over the years to the tune of well over a billion dollars. This year alone, the FBI notes, Lazarus Group has stolen more than $200 million in crypto. The blockchain is inherently trackable, and so the feds know the addresses to which the funds were moved. The FBI is advising people to “be vigilant in guarding against transactions directly with, or derived from, those addresses.”

As for what North Korea is doing with all that crypto, experts speculate that the nation is funneling the funds into its nuclear weapons program. Kim Jong-un is traveling to Russia this month where he is expected to discuss supplying weapons to fuel Vladimir Putin’s ongoing invasion of Ukraine, which U.S. officials have warned will lead the nation to “pay a price.”