The document claims U.S software was compromised days before 2016 presidential election.
A 25-year-old federal contractor has been charged in the United States with leaking classified information to a digital media outlet.
Reality Leigh Winner, who worked at the Pluirbus International Corp in Augusta, Georgia, is accused by the U.S. Justice Department of mailing information to the online magazine, The Intercept.
The publication has published previous explainers regarding NSA whistleblower Edward Snowden’s government leaks.
It also encourages others to come forward and offers advice to those who wish to share secret information.
Winner had been employed at the NSA facility in Georgia since February.
She was arrested on Saturday for allegedly "gathering, transmitting or losing defense information."
The FBI says Winner accessed the report on May 9 and then sent it to The Intercept.
The magazine printed an article about the top secret NSA document on Monday but says it was provided anonymously.
The report alleges that Russian military-intelligence launched a cyberattack on at least one U.S. voting-software supplier just days before November’s election and sent so-called phishing emails to dozens of election officials.
Prosecutors said Winner admitted to leaking the classified document intentionally when she was confronted with the allegation.
Responding to the news of her detention, The Intercept issued a statement saying the U.S. government has chosen to name Winner.
It also said the release of her affidavit and search warrant “contain unproven assertions and speculations designed to serve the government’s agenda ... Winner faces allegations that have not been proven ... We take this matter with the utmost seriousness ... and will make no further comment at this time.”