ROCKLAND — Confidential information of patients who have been treated by the city’s emergency medical services may have been impacted by a breach of computer servers with the company that handles billing.

The city made the announcement Monday, June 13.

Comstar, the ambulance billing service for the City of Rockland, discovered suspicious activity related to certain servers within its network, according to the city. Comstar immediately started an investigation which determined they were subject to a cyber-attack that impacted patient accounts. The review confirmed Rockland EMS files were impacted and information may have been impacted by this incident includes, name, date of birth, medical assessment and medication administration, health insurance information and social security number.

Comstar is offering you access to credit monitoring and identity theft restoration services at no cost. To receive more information on these services or the breach of information, call the Comstar assistance line at 877-587-4280, Monday through Friday, 9 a.m. to 9 p.m. EST.

Rockland Fire Chief Christopher Whytock said the company initially notified the city in April of the event that occurred March 26. Comstar initially did not believe patient information had been accessed but hired a firm that investigated which confirmed the cyber attack.

The chief said out of an abundant of caution, Comstar made the announcement. Comstar has been handling ambulance billing for the city for the past year-and-a-half.