The U.S. announced charges on Thursday against five individuals involved in North Korea’s use of remote IT professionals to finance the regime’s nuclear ambitions and offered a reward for information regarding the overseas workers.

The Justice Department said in a press release that it unsealed charges against U.S. national Christina Chapman, Ukrainian national Oleksandr Didenko and three overseas DPRK workers going by the aliases Jiho Han, Chunji Jin and Haoran Xu for their involvement in defrauding over 300 companies in a years-long campaign.