The U.S. has offered rewards of up to five million dollars for information about a group of North Koreans involved in a scheme to use false identities to gain illicit employment with U.S. companies. 

The U.S. State Department said on Thursday that it is seeking information about three North Korean IT workers using the aliases Jiho Han, Chunji Jin and Haoran Xu, who illegally obtained telework employment with U.S. companies using the identities of more than 60 U.S. citizens.

The illicit scheme reportedly generated at least six-point-eight million dollars for North Korea.

The department also said that from October 2020 to October 2023, U.S. national Christina Chapman helped the trio obtain work as remote software and applications developers with companies in a range of sectors and industries.

It said that the North Koreans had also attempted, but failed, to gain similar employment at two U.S. government agencies, adding the three were linked to the North’s Munitions Industry Department, which oversees the development of the country’s ballistic missiles.