No victims of crime or financial fraud due to Optus cyber attack, CEO says

The Optus boss claims none of the customers who had their data breached has fallen victim to misuse of their exposed details.

Kelly Bayer Rosmarin told the Australian Financial Review's Business Summit the premeditated and "highly motivated" attack shouldn't have breached the company's defences.

"But given how inevitable these types of attacks are, I'm relieved we were able to act fast to ensure that ultimately the data that was exposed was not successfully used to harm any customers," she said.

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Nearly 10 million Australians had personal data exposed in the hack last October but 2.8 million of those were seriously impacted with passport, drivers licence and Medicare numbers breached.

But despite the large number of customers impacted, Bayer Rosmarin claimed no customers had fallen victim to the misuse of their data.

"Not a single customer has suffered any financial loss or fallen victim to a crime through misuse of the data," she said.

"This outcome should reassure all of us about what a strong and fast and collaborative response can achieve."

Optus is facing class action complaints following the breach and several government reviews.

The hack was one of many late last year, including health insurer Medibank, and sparked the federal government to introduce heft fines for major corporations who are subject to serious or repeated breaches.

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Bayer Rosmarin claims the telco did everything it could to protect customers and be transparent about the hack.

"We were being transparent, open and honest. We were apologetic and accountable," she said.

"We did more than any other company in a cyberattack before had done, and we did it much quicker.

She said the company sent out 16 million customer communications with 110 bespoke messages for different cohorts.

"There were a couple of messages that, when you read them, you thought: 'Oh, this looks like it's been written by someone who hasn't slept in four days'," she said.

"So I wish every single one of those 110 communications had been to our usual level of quality."

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Bayer Rosmarin added the telco is looking towards the future and implementing further protections to their cyber security.

She said the company has introduced a bug bounty program and is undergoing cyber-attack simulations.

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