The Illinois Department of Human Services said it experienced a "privacy breach" through a phishing campaign that was sent to employee emails April 25. Hackers gained access to files that included Social Security numbers of 4,701 customers and three employees, IDHS said. Hackers also accessed public assistance information for more than 1.1 million customers. That information included names, public assistance account number,s some combination of addresses, dates of birth, Illinois State Board of Education Student Information System ID numbers, Recipient Identification Numbers and cellphone numbers. IDHS said it worked with the Illinois Department of Innovation and Technology to investigate the extent of the breach and to determine which individuals were affected. Written notices were sent to all clients and employees whose information was accessed.