Southern Water cyberattack expected to hit hundreds of thousands of customers

Southern Water disclosed that a January cyberattack—claimed by the Black Basta ransomware group—resulted in theft of personal and HR data affecting an estimated 5–10% of its customers and an undisclosed number of staff; exposed items include names, dates of birth, national insurance numbers and bank account details, and the company is notifying affected individuals, offering credit-monitoring, and coordinating with regulators and law enforcement.