Russian hackers took aim at Dallas County's Web servers, possibly trying to access voter registration rolls, before the November presidential election, officials said Wednesday.

"They didn't infiltrate our system," said Toni Pippins-Poole, the county's elections administrator. "They couldn't get in."

If the hackers had been able to manipulate or delete the county's registered voter database — which contains names, dates of birth and addresses for 1.3 million voters — that could have caused chaos on Election Day, said Dallas County Commissioner John Wiley Price.

"The fact that there were that many attempts says they expected to disrupt," Price said. "If you disrupt the voter file, then when people are trying to validate at the polls, you got mass confusion."

In early October, the U.S. Department of Homeland Security alerted local elections offices about roughly 600 Internet Protocol addresses that were suspicious and possibly linked to Russian hackers, Pippins-Poole said. The county scanned its system for those IP addresses and found 17 matches that had tried to gain access to its servers, she said.

Federal authorities told the county that at least some of the 17 were confirmed Russian IP addresses, Pippins-Poole said.

The county backs up its voter registration rolls with the Texas secretary of state, which would help in case of a successful breach, Pippins-Poole said.

Russia's cyberattack targeted electoral systems in at least 39 states — a much more extensive infiltration than previously known, Bloomberg reported Tuesday. The revelations come as U.S. counterintelligence investigators continue an inquiry into whether the Russians attempted to meddle in the election.

"They're coming after America," former FBI Director James Comey said last week before the Senate intelligence committee investigating Russian interference in the election. "They will be back. Because we remain — as difficult as we can be with each other, we remain that shining city on the hill. And they don't like it."

It's unclear whether Russians targeted other Texas counties.

Collin and Tarrant county officials said they found no such attempts. Tarrant County scanned its system for the feds' list of suspicious IP addresses but found no attempts, said Stephen Vickers, the county's elections administrator.

Federal investigators identified some suspicious IP addresses and other digital clues after a cyberbreach in Illinois. In July 2016, a contractor there detected unauthorized data leaving the state's voter database, resulting in 90,000 records being compromised, Bloomberg reported.

Dallas County blocked the IP addresses that the feds provided, said Stanley Victrum, the county's chief information officer.

Since 2014, the county has spent $1.23 million on cybersecurity upgrades such as encryption enhancement, antivirus tools and scanners. The county spends an additional $566,000 each year on maintenance, operation and staff salaries for its IT security team, Victrum said.

"We have foreign players that try to come in all the time — almost every day," Victrum said. "The county Commissioners Court has made some pretty significant investments so that we could be safe."

America's elections system is decentralized — with at least 7,000 local elections jurisdictions — which is both good and bad for cyberdefense, said Diana Dolliver, a professor at the University of Alabama who specializes in cybersecurity.

That decentralization is a benefit because if hackers do succeed in infiltrating one jurisdiction, the rest of the country could be fine, Dolliver said. But it also means that security among often cash-strapped local and state governments can vary widely.

The best way to prevent cyberattacks is through investments in equipment and software upgrades, as well as training for staff on how to recognize "spear-phishing" emails so they don't click the links inside, Dolliver said.

"It's hard to make sure that everyone in the United States is doing that at a county level," Dolliver said. "On a national level, we need to start setting standards for cyberdefense."

Dallas County upgraded its defense systems after hearing of other counties falling victim to hackers who stole both data and, in one case, money, Price said. The county hired a consultant to review its vulnerabilities and find any gaps in security.

Commissioner Elba Garcia said it's crucial for governments to spend the necessary taxpayer dollars on technology even though it's expensive.

"This world is moving very fast with technology, and Dallas County needs to secure not only more advanced equipment, but the funds necessary to move at the same pace," she said. "It's hard to catch up."