North Korean-backed hackers were linked to a huge cryptocurrency robbery of $615 million (£469 million) from users of the popular online game Axie Infinity last month, according to the US.
Players may earn cryptocurrency by playing games or selling their avatars.
The hack is expected to be one of the most significant in the crypto world’s history.
According to US authorities, the breach was linked to a group known as “Lazarus,” which is thought to be managed by North Korea’s main intelligence office.
The FBI claimed in a statement on Thursday that “through our investigations, we were able to determine Lazarus Group and APT38, cyber actors affiliated with [North Korea], are responsible for the theft.”
In 2014, the Lazarus Group made headlines after they were suspected of hacking into Sony Pictures and releasing secret information to the public.
The organization asked that Sony pull its satirical comedy The Interview, starring Seth Rogen and James Franco, about a conspiracy to kill North Korean leader Kim Jong-un, from theaters.
Pyongyang is suspected of using stolen cash to finance its nuclear and ballistic missile programs in order to dodge international restrictions, according to a UN body that monitors North Korean sanctions.
“As it strives to defy stringent US and UN sanctions, the DPRK has increasingly relied on illegal activities – including cybercrime – to earn income for its weapons of mass destruction and ballistic missile programs,” a Treasury Department spokeswoman told Reuters.
North Korea’s hacking effort, according to a 2020 US military study, dates back to at least the mid-1990s and has evolved to a 6,000-strong cyber warfare squad known as Bureau 121, which works from Belarus, China, India, Malaysia, and Russia.
North Korean hackers stole about $400 million (£291 million) in digital assets in at least seven assaults on cryptocurrency platforms in 2021, according to blockchain analysis firm Chainalysis, making it one of the most successful years on record for cyber-criminals in the isolated east Asian state.