Optus boss says ‘skilled criminal’ behind cyberattack, admits telco lost customers

“Of course, in the immediate aftermath, there were customers who decided to leave us and that is understandable,” Rosmarin said. “But I think some reports were greatly exaggerated. We are already back in a position of being net customer positive, or growing our customer base.”

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Last month, the federal government considered banning ransom payments to cyber criminals because it could encourage more hacking attempts, such as the one that health insurer Medibank suffered last year.

But as experts predict a further escalation in cybercrime this year, Rosmarin said it was not feasible to rule out paying ransoms.

“Everyone has a policy of not paying ransoms, but it’s too absolutist to say ‘never’, given that the evidence doesn’t suggest that,” she said.

Narelle Devine, Telstra chief information security officer, Asia Pacific, also said there were instances where payment of a ransom may be justified. “There are some very small, niche cases where there might be some circumstances where companies go, ‘actually, now we need to do that’.”

Rosmarin said she could not divulge further details about the cyberattack because there was an ongoing criminal investigation into the matter.

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