The number of North Korean-linked hacks of cryptocurrency platforms rose to a record high in 2023, though the actual amount of funds stolen dropped around 40%, a report Wednesday from blockchain analysis firm Chainalysis showed.

In a series of 20 hacks throughout the year, cybercriminals linked to the Democratic People’s Republic of Korea siphoned slightly more than $1 billion worth of cryptocurrency, compared to $1.7 billion in 2022. North Korean hackers often target cryptocurrency to raise money as a way around international sanctions, according to U.S. officials.

The drop in funds stolen by North Korean hackers mirrors a larger trend in the cryptocurrency security landscape: an overall decline in hacks of the once-lucrative decentralized finance, or DeFi, protocols. In 2023, the total amount stolen from DeFi protocols was $1.1 billion, a 64% decrease from the $3.1 billion pilfered in 2022, according to Chainalysis.