Unlimited Technology Systems, which processes financial and revenue cycle data for US specialty healthcare providers, disclosed on July 20 that hackers accessed patient files for five days in October 2025. The breach, detected on October 19, 2025, exposed personal information of 3.8 million patients, including full names, Social Security numbers, dates of birth, driver's license scans, insurance details and medical records, according to a notice filed with the U.S. Department of Health and Human Services on July 1.

The company serves 4,500 clinics and 6,500 specialty healthcare providers and processes more than $70 billion in net healthcare charges annually. The unauthorized access occurred between October 5 and October 10, 2025. No ransomware or extortion group has claimed responsibility, and Unlimited Technology Systems said it has not identified the attackers. Affected patients were offered identity monitoring services through Kroll, Bill Toulas reports for BleepingComputer.