The United States has sanctioned two individuals and two entities for their alleged roles in a fraud network used by North Korea to infiltrate U.S. companies with hackers posing as legitimate job seekers. 

The U.S. Treasury Department’s Office of Foreign Assets Control announced on Wednesday that it imposed sanctions on a North Korean citizen named Kim Ung-sun, as well as a Russian national, for allegedly violating U.S. sanctions against Pyongyang. 

A North Korean trading company and a China-based firm were also added to the U.S. sanctions list.

Under Secretary of the Treasury for Terrorism and Financial Intelligence John Hurley said the North Korean regime continues to target American businesses through fraud schemes involving overseas IT workers, who steal data and demand ransom.

Hurley added that the Treasury is committed to protecting Americans from these schemes and holding the guilty accountable.

The Treasury said its action is part of an effort by the entire U.S. government to counter the North’s wide-ranging revenue generation schemes, in close coordination with the country’s allies and partners.