A ransomware attack that hobbled a Georgia county government in early October reportedly disabled a database used to verify voter signatures in the authentication of absentee ballots.

It is the first reported case of a ransomware attack affecting an election-related system in the 2020 cycle. Federal officials and cybersecurity experts are especially concerned that ransomware attacks — even ones that don't intentionally target election infrastructure — could disrupt voting and damage confidence in the integrity of the Nov. 3 election.

The Oct. 7 attack on Hall County, in the northern part of th...