Officials in Pennsylvania and Ohio tell CNN they are working closely with the Department of Homeland Security to protect their elections systems from cyberattacks and breaches.

Ohio is going one step further.

“We even asked the National Guard to attempt to penetrate our databases,” said Joshua Eck, a spokesman for Ohio Secretary of State Jon Husted. “We’ve had a number of really positive tests. It has gone well and we’ve been able to find vulnerabilities and fix them.”

A pair of cyberattacks on Illinois’ and Arizona’s voter registration databases over the summer spurred the Obama administration to ring the alarm bells for states as they prepare for what has already been a chaotic campaign.

And top Democrats on the House and Senate intelligence committees publicly accused the Russian government of seeking to alter the election.