Skender Construction, a Chicago-based general contractor that works across sectors like healthcare, multifamily, education, and retail, was the victim of a ransomware attack that affected 1,067 people, the company revealed in an April 5 filing with the Maine Attorney General’s office.

The firm discovered the attack on March 15, according to a letter from Jerry Ball, Skender’s chief operating officer, which will be sent to affected individuals. Skender believes that the attacker only pursued money, and not information on its systems. However, based on an investigation, the contractor believes that identifiable information of individuals in its system may have been accessed. This could include names, addresses, dates of birth and Social Security numbers, along with direct deposit, driver’s license, passport,  and potentially health information, if provided to the company.