Transcript for Attacking the vote: how American votes can be 'hacked'

Massive effort to meddle in the election. The Russian campaign to under mine our elections ongoing and the timing could not be worse. On the eve of one of the most closely watched and consequential elections of our lifetime. One voter caught in the chaos, Aaron Mcgee. We caught up with him at a trump rally. A staunch supporter of the president. Especially his stance on immigration. I've often referred to Donald Trump as the trump card. Mcgee's views informed in part by social media. He frequently consumes and shares posts that reenforce his political perspective. I think social media are just a reflection basically of what people think. Last year he shared a Facebook post from a page called "Stop all invaders" which was filled with anti-immigration rhetoric what he didn't know, what he thought was a pro-american post was actually created by a Russian. I had no idea that it was not a post made by an American. Or U.S. Permanent resident. It was all part of a years' long multi facetted Russian campaign attempts at hacking the voting system and robust campaign on social media that touched on hot button issues such as immigration, gun control and race relations. Was often about sewing the vision and about leveraging the controversies that are already existing in society. Just last month, a Russian woman, Elena khusyaynovaa was indicted alleged by part of a conspiracy behind that stop all invaders Facebook page post like Mcgee shares but she denied the allegation. Mcgee says it didn't work on him anyway. In no way whatsoever was a influenced. So far the special counsel Robert Mueller has inexcited 13 other Russians in their involvement in the disinformation campaign. Last year I travelled to Russia to see for myself what happens inside one of these so-called troll factories. I'm from ABC news in the United States. Cut. I was quickly turned away. But an under cover journalist provided us footage showing rows of troll inside the internet research agency which was later named in one of Robert Mueller's indictments. And the disinformation campaign was just the beginning. Next step, motivating Americans to take their frustrations off line and on to the streets. Conrad James an activist from Raleigh, North Carolina, says he was approached by a woman who claimed to represent black matters U.S. To his dismay he later learned they were an allegedly russian-group. They make the entire movement look bad. Who else was hooked like me by the same group. Now the lead up to this midterm election day American intelligence officials warn their subterfug. Reporter: Reporter: Has not stopped. This is culmination of two years of massive investment we have made in people and technology to ensure our platforms are safe and secure place for elections. Disinformation campaigns are by no mean it's the only threat to American democracy. Russia likely targeted all states in the elections in attempt to access databases guys valuable election information. In theory it could be startlingly easy. . This year hackers made headlines at defcon conference teaching an 11-year-old how to exploit website they created. You can change the name, the vote. Even the party. You can change whatever you wanted. The point was to show how vulnerable our election infrastructure really is. Could take me less than five minutes maybe or five minutes. Harry is one of the lead organizers this annual gathering of hackers. This is my first assisted hack. So this is connected to that behind. He brought with him a real voting machine that had been decommissioned few years ago. As he showed us Alzheimer's you kneel to tamper with it is a basic USB drive. Too took just a few moments. You're saying somebody who is voting that actually wants to create mischief can put it something in the machine. Correct. Because this whole area is voter accessible. What would you do just suck the data out of it. You can do whatever you want. You have the same unrestricted supervisor access. Elected officials say these concerns are over blown but you don't eefb actually have to be at a polling place to tamper with the vote. This is cloud security expert with red lock tracks how hackers a access voter databases on the internet. Show me how it works. This exclamation point has a known security issue. He sets up vulnerabilities that mimic those of state board of elections. It's a honey pot for hackers, if hackers find a way into cloud based servers they could tamper with voter registration data, voter rolls and potentially ballot files which tells the voting machines who is on the ballot and how to record the vote. If they exploit this host they can do whatever they want with the files on it. As a attacker don't need to go after the voting machine. As far as we know most attempts to breach board of election sights failed but in at least one state, Illinois, Russian hackers were able to access the electronic voter registration system potentially compromising the information of 76,000 citizens. I think we're more ready than ever but still lack the stand toord secure the ecosystem, not just the voting mushes but everything that supports it. Experts say there's more needs to be done to be protected against both hackers and cyber our democracy depends on it and. We'll be joining our power house political team for election coverage starting at 8:00 eastern tomorrow night.

This transcript has been automatically generated and may not be 100% accurate.