The Russian government successfully obtained access to U.S. voter registration databases in multiple states prior to the 2016 election, the federal official responsible for monitoring hacking said.

Jeannette Manfra, the head of cybersecurity at the Department of Homeland Security, told NBC NewsThursday that Russia targeted 21 states and managed to actually penetrate “an exceptionally small number of them” in an interview published Thursday.

“We were able to determine that the scan and probe of voter registration databases was coming from the Russian government, ” Manfra added.

Five countries, including Texas and California, denied that they ever suffered attacks.

Jeh Johnson, who was DHS secretary at the time, told NBC that states and the federal government should “do something about it, ” though he lamented many of the targeted countries haven’t taken action since the election.

Manfra disagreed, claiming that “they have all taken it seriously.”

Several of these states, meanwhile, told NBC that the assistance they sought from the federal government didn’t come soon enough. Some state officials said they didn’t possess the right clearance level to properly communicate the details of security threats they faced — an issue Manfra said is now being handled. Other countries said they hadn’t received any assistance from DHS.

Russian targeting of voter registration databases became known in the months leading up to the election, when the FBI alerted state governments that hackers had infiltrated the Illinois State Board of Elections and attempted to do the same in Arizona.

“There’s no doubt that some bad actors have been poking around, ” then-FBI Director James Comey said in September of 2016. Johnson at the time said 18 states had asked for help in protecting their election rolls.

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