Federal agencies issued criminal charges and sanctions Friday against nine Iranians accused of hacking sensitive information from hundreds of universities, private companies and U.S. government entities.

The Iranian defendants, accused of working at the behest of the Iranian government-tied Islamic Revolutionary Guard Corps, hacked the computer systems of about 320 universities in the U.S. and abroad to steal expensive science and engineering research that was then used by the Iranian government or sold for profit, prosecutors said.

More than 100,000 professors worldwide were targeted with spear-phishing emails, making the hacking scheme one of the largest state-sponsored cybercrime cases ever charged by the Justice Department, the Wall Street Journal reported.

The affected professors and universities were not identified.

The Justice Department said the hackers stole roughly 31 terabytes of academic research and intellectual property that was then sent to servers outside the United States for profit. That amount of data is said to far exceed the total content of the Library of Congress.

"Just in case you're wondering, they're not admiring our work," FBI Deputy Director David Bowdich said. "They're stealing it, and they're taking credit for it, and they're selling it to others."

"Just in case you're wondering, they're not admiring our work. They're stealing it, and they're taking credit for it, and they're selling it to others." — FBI Deputy Director David Bowdich

The information that was stolen, which was sold through two websites to customers in Iran, cost U.S. universities about $3.4 billion to procure and access.

The hackers are also accused of breaking into the networks of government organizations, including the Department of Labor, the Federal Energy Regulatory Commission, the United Nations and private sector entities, including 36 American companies, the Journal reported.

The Justice Department said the hackers were affiliated with an Iranian organization called the Mabna Institute, founded by two of the defendants, which prosecutors said contracted with the Iranian government to steal scientific research from other countries.

"By bringing these criminal charges, we reinforce the norm that most of the civilized world accepts: Nation-states should not steal intellectual property for the purpose of giving domestic industries an advantage," Deputy Attorney General Rod Rosenstein said in announcing the charges.

The defendants are unlikely to ever be prosecuted in an American courtroom since there's no extradition treaty with Iran. But the grand jury indictment, filed in a federal court in New York City, is part of the government's "name and shame" strategy to publicly identify foreign hackers, block them from traveling without risk of arrest and put their countries on notice.

"People travel. They take vacations, they make plans with their families," Bowdich said. "Having your name, face and description on a 'Wanted' poster makes moving freely much more difficult."

"Having your name, face and description on a 'Wanted' poster makes moving freely much more difficult." — FBI Deputy Director David Bowdich

On Friday, the U.S. Treasury Department also imposed sanctions against the nine defendants and the Mabna Institute, the Journal reported. The sanctions block their access to U.S. companies and entities, including financial transactions.

Tehran responded with Bahram Ghasemi, spokesman for the Foreign Ministry, condemning the move and calling it "provocative, illegal and without justification."

Ghasemi said the charges are "another sign of hostility of the U.S. government towards Iranian nation." He said the U.S will not take any benefit from the move aimed at "thwarting" scientific growth of Iran.

The Associated Press contributed to this report.