John Bolton speaks at Harvard Kennedy School's John F Kennedy Jr Forum in Cambridge, Massachusetts, on September 29, 2025.

An Iranian hacking campaign targeting John Bolton and other former government officials included threats against Bolton to expose him and cause him the kind of problems that crippled Hillary Clinton’s 2016 presidential campaign.

The indictment of Bolton for allegedly mishandling sensitive national security information suggests that the Iranian hackers got their way.

Investigators have been laboring on this Bolton case since 2021, when the FBI began assessing potential damage from the Iranian hack and raised questions about whether Bolton’s practice of sending diary entries through email broke the law, according to people briefed on the probe.

Early in that investigation, Bolton’s assistant told the FBI that the purported hacker was threatening to expose sensitive documents.

He received a taunting message about his email being hacked, calling it potentially “the biggest scandal since Hillary’s emails were leaked, but this time on the GOP side!”

“Good luck Mr. Mustache!” one message said, according to a person who described investigative documents.

While Bolton was in touch with US authorities about being hacked at this time, prosecutors say he didn’t tell the FBI he had used the email account to send classified information to his family members.

The FBI and national security lawyers in Maryland and Justice Department headquarters formally opened an investigation in 2022 and have worked since to try to assess the potential damage, sources said.

For prosecutors and FBI investigators, part of their effort has focused on keeping the case out of the roiling politics looming over the Justice Department as President Donald Trump has publicly pushed for the prosecution of his political enemies, which includes Bolton.

Unlike prosecutions brought against James Comey, former FBI director, and Leticia James, the New York attorney general, the Bolton case has maintained the support of career prosecutors and investigators, people briefed on the matter said.

The federal investigations of Bolton have stretched over two Trump administrations and the Biden administration.

The initial probe began as criminal and civil cases as the outgoing Trump administration sought first to block Bolton’s 2020 memoir and investigated whether Bolton violated the law by including information the administration said was classified. That initial case was closed in 2021, just as investigators began the current case that they have now brought in federal court.