National Australia Bank chief executive Ross McEwan backs Medibank's decision not to pay cyberhackers ransom demand

The cyberhacking crisis at Medibank is deepening with the private health insurer confirming that customer files have been released on the dark web.

Medibank is refusing to pay the ransom demand, expecting that more files will be released by the cybercriminal.

The head of the National Australia Bank Ross McEwan has warned all companies need to be vigilant about cyberattacks while backing Medibank's decision not to pay a ransom.

After delivering a full year profit of  $6.89 billion, Mr McEwan told me the NAB repels millions of attacks every month.

Listen to the interview on The World Today.