Australia Today Update: Medibank today conceded all of its 4 million customers have been impacted by its cyber attack

Medibank today conceded all of its 4 million customers have been impacted by its cyber attack. The CEO again apologized while the health insurer's shares plunged when its trading halt ended.

Medibank shares were sent into a tailspin when the insurer made come back on the stock market this morning, diving as much as 16% as the company confirmed the hackers had accessed the personal information and sensitive health data of all 4 million of its customers.

I'm in Madibing as well, and I feel ripped off. With our security system, we should be ahead of the game, not behind the game. Yesterday the CEO was calling it a distressing development when he feared the worst.

I'm now operating under the potential that all of our customers are impacted today. No words pulling out of a planned TV interview this afternoon. Instead, a statement. Our investigation has now established the criminal has access to all customers. And there was one more. I apologize unreservedly. They have names, addresses, birth dates, phone and Medicare numbers, and most private of all, details of any procedures undertaken.

I think something that no customer really wants to hear, is that their medical data could be out there about potentially sensitive operations they've had or potentially sensitive medical issues they've experienced. Another cyber expert says it's now time for drastic action.

I can't believe I'm saying this, but I think this might be one of those cases where it might be better if the rent and what's paid an. Insurer without cyber insurance. Medibank believes its response to this cyber attack will cost anything up to $35 million. And with the potential of lawsuits and penalties, that figure will surely blow out.

As Medibank struggles to protect its reputation, Optus is telling its customers how good it was against hackers. A global message. We went public early. We engage with the government openly and quickly, and we listened, we learned, and we respect in real-time.