The four men, using fake social media accounts and working on behalf of the Iranian Revolutionary Guard Corps, sought to deploy malware that would provide them covert access to the targets' computers and networks, prosecutors said.
"She chose to turn against the United States and shift her loyalty to Iran", said Jay Tabb, the FBI's executive assistant director for national security. She was not arrested.
The FBI said Wednesday that it's possible Witt remains a threat, and her former colleagues have been apprised of the charges against her.
According to the Justice Department, Witt entered the Air Force in 1997 and left in 2008.
Prosecutors say that Iranian intelligence recruited Witt in 2012 when she attended a conference in Iran called "Hollywoodism", organized by Iranian company New Horizon Organization and sponsored by the IRGC.More news: S.Korea pushes back at Trump claims about money for troops
The indictment claims Witt not only revealed to Iranian officials the existence of highly-classified intelligence programs, but also provided them with the true identity of at least one American intelligence officer. That group has been designated by the USA government as promoting terrorism.
Iranian hackers then used that information to target those individuals with cyberattacks, the Justice Department said.
The announcement, which also included sanctions on the New Horizon Organization, organization officials, and a company tied to the hacking effort, came on the opening day of a US-led global conference in Warsaw, Poland aimed at boosting pressure on Tehran.
She defected to Iran in 2013 after being invited to two all-expense-paid conferences in the country that the Justice Department says promoted anti-Western propaganda and condemned American moral standards. She was also a Defense Department contractor until 2010. Prosecutors say that Individual A worked as a spotter and assessor for Iranian intelligence.
They declined to say to what extent these disclosures compromised US intelligence operations targeting Iran.
Last November, US President Donald Trump re-imposed all sanctions on Iran that had been suspended due to the 2015 Joint Comprehensive Plan of Action (JCPOA) nuclear agreement. "She continued to travel".More news: Australia's Lower House Passes Asylum Bill in Historic Defeat for Government
She eventually did, with help from Individual A, in August 2013.
That year, an unidentified person contacted her and remarked that she was well-trained.
"I loved the work, and I am endeavoring to put the training I received to good use instead of evil", she allegedly told her IRGC contact. "Thanks for giving me the opportunity", according to the indictment.
She also conducted online research, including on Facebook, to create information "packages" on her former colleagues in the USA intelligence community.
"Our intelligence professionals swear an oath to protect our country, and we trust them to uphold their oath".
"It is a sad day for America when one of its citizens betrays our country", said Assistant Attorney General John Demers at a briefing to make public the charges.More news: Cardi B deletes Instagram account hours after winning Grammy Award
The Justice Department officials would not say whether Witt's prosecution was connected to an American-born Iranian television anchorwoman who was recently released after being detained by the Federal Bureau of Investigation as a material witness in an undisclosed US case. She has not been charged with any crimes. The statute generally requires those witnesses to be promptly released once they are deposed.