In 2016, Russian Hackers Successfully Penetrated U.S. Voter Rolls

Voter rolls of several states were accessed by Russian hackers ahead of the 2016 elections, according to DHS.

According to a top U.S. cybersecurity official, Russia successfully hacked voter registration rolls in several states ahead of the 2016 presidential election, though there is no evidence that any rolls were altered.

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."

Former DHS secretary Jeh Johnson 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."

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.

Johnson also said he is concerned that states have not done enough since the 2016 elections, but Manfra disagrees, saying "they have all taken it seriously."

Some state officials had opposed Johnson's designation of electoral systems as critical infrastructure, viewing it a federal intrusion. Johnson said that any state officials who don't believe the federal government should be providing help are being "naïve" and "irresponsible to the people that [they're] supposed to serve."