In December, internet giant Yahoo revealed that data from more than one billion user accounts had been stolen.
Documents obtained by the ABC show that among them, are over 3-thousand private accounts belonging to Australian ambassadors and the AFP officers, as well as high-profile politicians including Victorian Premier Daniel Andrews and Social Services Minister Christian Porter.
The stolen database contains email addresses, passwords, and other personal information.
Professor Richard Buckland is a Professor of Cyber Security at the University of New South Wales.
He's speaking to NewsRadio's Sandy Aloisi.