Researchers for FireEye and other firms have reported suspected Iranian disinformation on most major social media platform — Facebook, Instagram, YouTube, Google+ and others — and on stand-alone websites, as well. In May, FireEye also alleged that U.S. news sites may have been tricked into publishing letters to the editor penned by Iranian operatives.

The firm’s analysis spotted a number of instances where letters in newspapers in Virginia and Texas appeared to share similar characteristics to accounts on Twitter believed to be part of an Iran-based disinformation network. FireEye also catalogued fictitious Twitter personas used by Iranians that included a Harvard University student, a Michigan bodybuilder and an Iranian American woman from Seattle.

Some Iranian Twitter accounts, FireEye found, even sought to impersonate U.S. political candidates, including a California Republican who ultimately lost the general election for Congress. That account tweeted about the confirmation hearing for U.S. Supreme Court Justice Brett M. Kavanaugh and a British royal wedding before beginning to promote Iranian interests, including tweets condemning the Saudis’ killing of Washington Post contributing columnist Jamal Khashoggi.