North Korean hackers have stolen $1.5 billion in cryptocurrency in a single heist, making it the largest crypto hack on record, security experts told CNN.

The Lazarus Group, a cybercrime syndicate linked to North Korea, has long been a thorn in the side of the crypto industry. Since 2017, the group has stolen over $6 billion in digital assets, funneling the proceeds into the country’s ballistic missile program. The Bybit heist alone accounts for nearly a quarter of that total.

Researchers spot the $1.4 billion stolen from Bybit moving through cryptocurrency wallets that were used in earlier heists attributed to North Korea's Lazarus hacking group.