One of Australia’s largest private health insurers has completed a cyber security overhaul, months after a major hacking scandal.

Medibank has resumed all customer-facing platforms on Saturday morning after temporarily shutting down its IT systems to improve security.

“All customer-facing platforms have been fully tested with IT security experts from Microsoft and are operational with enhanced security protections,” the company said in a statement.

“The IT systems were back online ahead of schedule at 6.15am (AEDT) on Saturday 10 December 2022. Customers can now access Medibank systems as usual, including the website and apps, and they can use HICAPS when claiming again.”

All retail stores and call centres will remain closed until Monday.

Medibank’s IT systems had been offline since 8:30pm on Friday in a planned procedure as part of Operation Safeguard, which was carried out at the company’s Melbourne headquarters with IT security experts from Microsoft.

The overhaul was in response to a massive cyber attack in October.

Russian cyber criminals hacked Medibank’s customer database and stole the health records of almost 10 million current and former customers.

The hackers have since published the entirety of the data on the dark web, including records of procedures and conditions related to abortions and mental health disorders, following Medibank’s refusal to pay a $15 million ransom.

The company said there has been no further suspicious activity detected inside its systems since the attack.

By Mibenge Nsenduluka in Canberra