Russians penetrated U.S. voter systems, top U.S. official says

The U.S. official in charge of protecting American elections from hacking says the Russians successfully penetrated the voter registration rolls of several U.S. states prior to the 2016 presidential election.

In an exclusive interview with NBC News, Jeanette Manfra, the head of cybersecurity at the Department of Homeland Security, said she couldn't talk about classified information publicly, but in 2016, "We saw a targeting of 21 states and an exceptionally small number of them were actually successfully penetrated."

Jeh Johnson, who was DHS secretary during the Russian intrusions, said, "2016 was a wake-up call and now it's incumbent upon states and the Feds to do something about it before our democracy is attacked again."

The U.S. official in charge of protecting American elections from hacking says the Russians successfully penetrated the voter registration rolls of several U.S. states prior to the 2016 presidential election.

In an exclusive interview with NBC News, Jeanette Manfra, the head of cybersecurity at the Department of Homeland Security, said she couldn't talk about classified information publicly, but in 2016, "We saw a targeting of 21 states and an exceptionally small number of them were actually successfully penetrated."

Jeh Johnson, who was DHS secretary during the Russian intrusions, said, "2016 was a wake-up call and now it's incumbent upon states and the Feds to do something about it before our democracy is attacked again."DHS cybersecurity head: 'No doubt' Russians penetrated voter registration systems 0:26"We were able to determine that the scanning and probing of voter registration databases was coming from the Russian government."

NBC News reported in Sept. 2016 that more than 20 states had been targeted by the Russians.

There is no evidence that any of the registration rolls were altered in any fashion, according to U.S. officials.

In a new NBC News/SurveyMonkey poll, 79 percent of the respondents said they were somewhat or very concerned that the country's voting system might be vulnerable to computer hackers.

In January 2017, just weeks before leaving his post, Johnson declared the nation's electoral systems part of the nation's federally protected "critical infrastructure," a designation that applies to entities like the power grid that could be attacked. It made protecting the electoral systems an official duty of DHS.