North Korean information technology workers are suspected of infiltrating more than 300 U.S. companies, using aliases to gain at least $6.8 million for their government from remote-work jobs, the Justice Department said Thursday.

The department unsealed charges against several individuals, including an Arizona woman who is accused of helping the North Korean IT workers from around October 2020 to work remotely from abroad by using stolen or borrowed U.S citizens' identities.

Many of the affected are leading U.S. companies, according to the indictment. Without stating corporate names, it said they included a national television network, a "premier" Silicon Valley technology entity and an "iconic" car manufacturer, as well as "one of the most recognizable media and entertainment companies in the world."

In a related development, the State Department on Thursday said it will provide a reward of up to $5 million for information on three North Korean IT workers using aliases Jiho Han, Chunji Jin and Haoran Xu, as well as their manager Zhonghua.

It said the individuals are linked to North Korea's Munitions Industry Department, which oversees the development of its ballistic missiles and weapons production.

Related coverage:

North Koreans worked on Japanese, U.S. anime shows, report says