Ohio’s Union County suffers ransomware attack impacting 45,000 people

A ransomware attack hit Union County, Ohio, resulting in the theft of Social Security and financial data, with officials notifying 45,487 residents and staff about the breach. The incident, which occurred between 6 May 2025 and 18 May 2025, prompted Union County to launch an investigation with the help of nationally recognised third-party cybersecurity and data forensics consultants to secure its network and determine the scope.

By 25 August 2025, officials had finished reviewing the breach and began notifying affected individuals. Stolen data includes names, Social Security numbers, driver’s licence numbers, financial account information, fingerprint data, medical information, passport numbers and more. The article notes that no ransomware group has claimed responsibility for the attack.

The breach followed discoveries that the security incident involved ransomware detected on 18 May 2025, after the county had learned of the intrusion earlier in May.