WASHINGTON (Reuters) - U.S. officials said late Friday that the Iranian hackers behind a wave of threatening emails sent to thousands of Americans earlier this month successfully accessed voter data. The statement, issued jointly by the FBI and the Department of Homeland Security’s Cybersecurity and Infrastructure Security Agency (CISA), partially confirms the authenticity of a video distributed as part of a disinformation campaign that briefly drew attention when it became public last week. The campaign - which consisted of thousands of threatening emails sent to random U.S. voters in the name of a pro-Trump far right group - featured a video in which a hacker purported to demonstrate how they could cause havoc by breaking into a voter registration records. Experts who examined the footage said it amounted to little more than an attempt to scare voters about the integrity of the Nov. 3 contest, but the question of whether the hackers actually did break in anywhere had gone unanswered until now. CISA and the FBI confirmed Friday that “the actor successfully obtained voter registration data in at least one state.” The state was not identified, although purported personal details of Alaska voters were briefly flashed on the video. The FBI, CISA, and the Alaska Division of Elections did not immediately return messages seeking comment. CISA and the FBI said the Iranian hackers also scanned a number of other states’ election sites for vulnerabilities.