North Korean hackers have stolen an estimated US$3 billion worth of cryptocurrency since 2017, using the funds to support the regime's nuclear and missile programs, a Microsoft report showed Thursday.

Of that amount, between $600 million and $1 billion was stolen just last year, based on Microsoft's Digital Defense Report for 2024.

The report highlights that these stolen funds have financed over half of Pyongyang's nuclear development efforts.

Since last year, Microsoft has identified several new North Korean hacking groups -- Moonstone Sleet, Jade Sleet, Sapphire Sleet and Citrine Sleet, which have been targeting cryptocurrency organizations.

In particular, Moonstone Sleet has developed a custom ransomware variant and deployed it against unidentified entities in the aerospace and defense sectors for both intelligence gathering and financial gain.

Microsoft analysts said the emergence of new hacking groups suggests that the North Korean regime is expanding its involvement in ransomware activities, increasing the use of cybercriminal tools to bolster the regime's financial resources and advance its strategic interests.

"Nation-states are becoming more aggressive in the cyber domain, with ever-growing levels of technical sophistication that reflect increased investment in resources and training," said Tom Burt, Microsoft's vice president of customer security and trust.

Microsoft also warned of rising cyber threats by state-backed actors, especially those related to Russia, China and Iran, ahead of the US presidential election and amid persistent geopolitical conflicts in Europe and the Middle East. (Yonhap)