North Korean hackers have turned to a sanctioned Russian cryptocurrency exchange to launder over $100 million in stolen virtual assets, demonstrating their ability to get around efforts to curb funding for Pyongyang’s nuclear ambitions.

The DPRK-linked Lazarus Group compromised over 5,500 virtual wallets in its campaign targeting Atomic Wallet, a digital wallet service, blockchain analysis firm Elliptic said in a report Tuesday.

The $100 million sum is significantly larger than the initial estimate of $35 million reported last week, the first major cryptocurrency theft publicly attributed to Lazarus since last June’s Horizon Bridge heist.

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