Washington — Federal investigators are looking into whether Iranian hackers targeted individuals associated with the Trump and Biden-Harris campaigns, three people familiar with the investigation confirmed to CBS News.

The FBI launched the probes in the early summer, after both presidential campaigns experienced attempted phishing schemes targeting people on the campaign, the sources said. Iran-backed cybercriminals are the potential suspects. The Washington Post first reported the details of the FBI's investigation into the campaigns.

The news comes after the FBI confirmed in a brief statement Monday it was investigating the Trump campaign's allegations that had been targeted by Iranian hackers. The bureau declined to comment further.

Former President Donald Trump's presidential campaign said in a statement Saturday that it had been hacked and suggested Iranian actors were involved in stealing and distributing sensitive internal documents.

Though scant on details linking the alleged hack to Iran, the assertion followed the publication of a new report by Microsoft that cited an instance of an Iranian military intelligence unit in June sending "a spear-phishing email to a high-ranking official of a presidential campaign from a compromised email account of a former senior advisor."

Trump campaign spokesperson Steven Cheung blamed the hack on "foreign sources hostile to the United States," according to a statement released Saturday.

CBS News reached out to the Trump campaign for further comment on Monday.

A Harris campaign official told CBS News, "Our campaign vigilantly monitors and protects against cyber threats, and we are not aware of any security breaches of our systems."

Aaron Navarro contributed to this report.

In:
• Kamala Harris
• Donald Trump
• FBI