Iranian hackers who sent a barrage of threatening emails to US voters last month were successful in accessing voter data from at least one state, according to a joint statement issued late last Friday by the FBI and the Department of Homeland Security’s Cybersecurity and Infrastructure Security Agency (CISA).

Although the state was not identified, alleged personal details of Alaska voters were briefly flashed in a video released by the hackers. The video accompanied a campaign that sent thousands of threatening emails to US voters disguised as a far-right pro-Trump group.

The security breach is the latest attempt targeting the 2020 US elections, US intelligence officials warned, including attempts to hit the campaigns of President Donald Trump and his opponent, Joe Biden.

Why it matters: During an impromptu press briefing Oct. 21, Director of National Intelligence John Ratcliffe announced the US government had determined Iran was behind an email campaign meant to intimidate voters and that some voter registration information was obtained by Iran, although no more details were provided. Attribution of attacks can sometimes take years. However, in the case of October’s incident, federal officials needed only days.