Justice Department charged four North Koreans with posing as IT workers to steal U.S. companies money, it said Monday.

The scheme involved thousands of workers who were dispatched by the North Korean government to find work as remote IT employees at American companies.

The U.S. Department of Justice and FBI on Monday announced an arrest and indictments targeting North Korea’s so-called “IT worker” program, where North Koreans obtain remote IT-related positions at more than 100 U.