Investigation comes amid rising fears that Iran has emerged as the most aggressive foreign election threat to U.S.

The Federal Bureau of Investigation has been investigating since June suspected Iranian attempts to hack people linked to both the Trump and Biden-Harris campaigns, according to a person familiar with the matter. At least three staffers on the Biden-Harris campaign were targeted with so-called spear-phishing emails intended to trick recipients into clicking on seemingly legitimate links or files in a bid to gain access to their internal communications, the person said, adding that the attempts took place before President Biden stepped aside for re-election and was succeeded by Vice President Kamala Harris as the Democratic nominee. The hacking attempts were apparently unsuccessful, the person said. The alleged efforts by Iran to hack Democrats in addition to former President Donald Trump’s campaign added to a series of rapid developments that appeared to expose a seemingly widespread and determined effort by the U.S. adversary to play a major role in disrupting the November election. On Monday afternoon, the FBI said in a statement it was investigating an apparently successful cyberattack that purloined internal documents from the Trump campaign that it disclosed to reporters on Saturday and blamed on Iran. Previously, the FBI only said it was aware of media reporting about the alleged hack.

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