Australian telecoms giant Optus on Monday said personal information and at least one valid form of identification of about 1.2 million customers was compromised in one of the country’s most significant cyber breaches.
The breach last month by an anonymous online account, which affected 10 million customers, equivalent to around 40% of Australia’s population, attracted harsh criticism from the government
Late Monday, Optus said the breach also affected expired IDs and personal information of about 900,000 customers and clarified that “the exposed information did not contain valid or current document ID numbers for some 7.7 million customers”.
The company’s parent Singapore Telecommunications Ltd (Singtel), said it assessed the massive breach’s cost at Australia’s second-largest telco.
Optus said it had informed the affected customers about the data breach after the Australian government urged it to speed up its notification to 10,200 customers whose personal information was made public.