Union County, Ohio hit by ransomware attack compromising resident data
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Union County, Ohio, was hit by a ransomware attack that compromised personal and financial information belonging to an undisclosed number of residents.
The cybersecurity incident occurred over a 12-day period between May 6 and May 18, 2025, but county officials did not publicly disclose the breach until September 2025.
The attackers encrypted county systems and extracted a substantial volume of sensitive data . The compromised data includes:
- Names
- Social Security Numbers (SSNs)
- Driver's license identification numbers
- Financial account information
- Dates of birth
- Fingerprint information
- Medical information
- Payment card information
- Passport numbers
The number of affected individuals is not disclosed.
The county completed its review of the impacted data on August 25, 2025 and began mailing notification letters to affected individuals on September 24, 2025.
Union County has deployed new advanced security tools and technologies, and forced a county-wide password reset for all systems and users.
Union County has a dedicated assistance hotline staffed with knowledgeable representatives familiar with the incident details. Residents with questions or concerns can contact the assistance line at 1-833-919-4739.
Update - as of 26th of September 2025, the county began sending out breach notifications to 45,487 local residents and county employees.
