Seven Chinese nationals were charged Monday in a "sinister" 14-year scheme to hack the computers of numerous high-ranking U.S. government officials, as well as defense contractors, political dissidents and critics around the world.

The defendants are accused of being part of a group known as Advanced Persistent Threat 31, or APT31, which works with the Chinese Ministry of State Security to conduct cyber espionage, according to the Justice Department.

Their targets allegedly included officials in the White House and the Justice, Commerce, Treasury and State Departments; Republican and Democratic members of Congress; and campaign staffers from both sides of the 2020 presidential race.

Some officials' spouses were also targeted, as were workers in vital sectors of the American economy, including military contracting, information technology and telecommunications, according to the Justice Department.

APT31 also allegedly went after academics and activists in Hong Kong, the U.S. and elsewhere, as well more than 400 government officials tied to the global Inter-Parliamentary Alliance on China.

The hackers even targeted Norway's governmment and a Norwegian internet service provider after leaders of Hong Kong's Umbrella Movement were nominated for the Nobel Peace Prize in 2018, according to the Justice Department.

"This case serves as a reminder of the ends to which the Chinese government is willing to go to target and intimidate its critics, including launching malicious cyber operations aimed at threatening the national security of the United States and our allies," Attorney General Merrick Garland said in a prepared statement.

Breon Peace, U.S. attorney for the Eastern District of New York, also called the alleged operation a "sinister scheme" that "victimized thousands of people and entities across the world, and lasted for well over a decade."

The hackers allegedly sent their targets malicious emails, including some that "spoofed" the name of a leading American TV journalist, according to a 27-page indictment unsealed Monday in U.S. District Court in Brooklyn, New York.

Some emails contained tracking links to help the hackers access computer routers and other devices, while others held files with various types of malware to let the hackers take control of the computers and access larger, private networks.

As part of the operation, more than 10,000 emails were allegedly sent to the work and personal addresses of various targets in the U.S. just between June and September 2018.

Computer networks were compromised at a leading U.S. provider of 5G network equipment, a public-opnion polling company and an aerospace and defense research company in Alabama, according to the Justice Department.

The defendants were identified as Ni Gaobin, 38; Ni Gaobin, 37; Cheng Feng, 34; Peng Yaowen, 38; Sun Xiaohui, 38; Xiong Wang, 35; and Zhao Guangzong, 38.

They were each charged with conspiracy to commit computer intrusions and wire fraud conspiracy, which carry a maximum total prison term of 25 years.

All are believed to be at large in China, according to the U.S. Attorney's Office for the Eastern District of New York.