Medibank yesterday informed that data including name, date of birth, address, phone number, and email addresses, of about 9.7 million current and former customers had been compromised.

Cyber security incidents in Australia have snowballed recently, with a government report suggesting there is one attack every seven minute.

As many as eight companies have reported cyber security breaches since September.

“We knew the publication of data online by the criminal could be a possibility, but the criminal’s threat is still a distressing development for our customers,” Medibank chief executive officer David Koczkar told Reuters in an emailed response today.

The country’s biggest health insurer also warned that its customers could be contacted by the criminal directly, adding that the Australian Federal Police was trying to prevent the sharing and sale of its customers’ data.