According to U.S. officials, North Korea has created a shadow workforce of IT workers who are involved in cybercrime operations and carry out large-scale crypto hacks.

These workers, who earn up to $300,000 per year, are spread across countries like Russia and China and have posed as recruiters or employees to infiltrate crypto firms.

With the help of these shadow workers, North Korean hackers have stolen over $3 billion in the past five years. The hackers have demonstrated technical sophistication in their attacks, including a cascading supply-chain attack last year.