Blockchain intelligence firm TRM Labs has reported that groups tied to the Democratic People’s Republic of Korea (DPRK) were responsible for roughly 33% of all crypto stolen through hacks in 2023.

According to a Jan. 5 report, TRM Labs said North Korean hackers potentially stole up to $700 million in crypto in 2023, with $600 million confirmed by its research. DPRK hackers have  stolen roughly $3 billion worth of crypto since 2017, suggesting that the country’s attacks involving digital assets increased in the last year.

The blockchain firm reported that the DPRK’s methods for money laundering were “constantly evolv[ing] to evade international law enforcement pressure.” Research suggested that the hackers almost always compromised users’ private keys or seed phrases, transferred funds to DPRK-controlled wallets and then swapped the assets for Tether ( USDT ) or Tron ( TRX ).

“North Korea’s hacking prowess demands continuous vigilance and innovation from business and governments,” said TRM Labs. “Despite notable advancements in cybersecurity among exchanges and increased international collaboration in tracking and recovering stolen funds, 2024 is likely to see further disruption from the world’s most prolific cyber-thief.”

Officials with the United States Treasury Department imposed sanctions on individuals and hacking groups they alleged were tied to North Korea, including Lazarus. Following the department’s sanctions against cryptocurrency mixers Tornado Cash and Sinbad, TRM Labs reported the DPRK “continued exploring other laundering tools.”

North Korean hackers stole USD 600 million in crypto in 2023, TRM Labs research shows. Read the story now: https://t.co/dyNmTcVzcP

— TRM Labs (@trmlabs) January 5, 2024

Related: Orbit Bridge hack pushes December crypto theft to nearly $100M

CertiK reported on Jan. 3 that there were roughly 751 breaches in 2023, which resulted in the loss of more than $1.8 billion in crypto — one-third of which DPRK hackers were alleged to be responsible. The Ethereum network reportedly recorded the most losses at $686 million over 224 incidents.

U.S. officials have often cited digital assets in their reasons for imposing sanctions on certain entities, including the terrorist group Hamas following its Oct. 7 attack on Israel. Cryptocurrency mixers have also been a particular target for lawmakers, who claim the technology is primarily used for illicit reasons.

Magazine: Tornado Cash 2.0: The race to build safe and legal coin mixers