Medibank reveals hack could affect all of its 3.9 million customers

Medibank has described the revelation that customers of its main brand could be affected as a ‘distressing development’, apologising to customers. Photograph: Lukas Coch/AAP

Australian health insurance giant Medibank has revealed the hack of customer records has affected more customers than first thought, with the CEO saying the company is acting on the assumption all customers are affected.

Earlier this month Medibank said it believed that only customers of its subsidiary ahm and those who were international students might have been affected by the hack of its systems. But now the company has said it has received files from the hackers that include main brand customers – widening the range of those potentially affected to 3.9 million.