Eversource reports data breach as companies across Connecticut struggle with cyber attacks.. Eversource joined M&T Bank and a number of other major U.S. companies to report. An Eversource substation in Greenwich, Conn. In August 2023, the company sent alerts to some Connecticut customers in energy efficiency programs that account data may have been exposed in an external vendor’s vulnerability to a widely used software platform. Eversource has become the latest company to deal with a cyber attack as banks, hospitals and businesses across Connecticut and the nation continue to struggle with data breaches. Third-party company: CLEAResult.