Patients have been told their personal medical records have been stolen during a disturbing cyber attack on a major network of healthcare services.

Partnered Health Group runs more than 60 clinics — including general practices and skin cancer centres — across Australia.

On Wednesday it revealed that a “malicious actor” had accessed data on June 23.

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“Our investigations to date have confirmed that personal information (including health information) was taken from some of the clinics in our network,” Partnered Health said, more than three weeks after the attack.

“We are continuing to investigate the extent to which personal information has been impacted by this incident and are communicating with patients from impacted clinics.

The stolen data may include names, date of births, addresses and contact details, Medicare numbers, private health insurance, medical information and treatment details.

“As a health services provider, we know our patients and our people trust us with personal and medical information and we sincerely apologise for any concern and inconvenience this may cause them,” Partnered Health said.

The incident has been reported the Australian Cyber Security Centre, the Office of the Australian Information Commissioner and police, “and we are continuing to work with the authorities”.

Partnered Health has also secured an interim injunction from the NSW Supreme Court to stop the accessed data being used or published.

The national healthcare network has released a list of 21 practices it says may have been caught up in the cyber intrusion, adding it believes the impact “differs across our clinics”.

- Blackburn Road Medical Centre

- Broadway General Practice

- Bundall Medical Centre

- Cardiff Medical Centre and Skin Cancer Clinic

- Castle Hill Family Doctors

- Champion Drive Medical Centre

- Chancellor Park Family Medical Practice

- Dromana Family Doctors

- Dural Medical Centre

- Joondalup City Medical Group

- Kealba Family Practice

- Mornington Family Doctors

- Noosaville Seven Day Medical Centre

- North Canberra Family Practice

- Park Beach Family Practice

- Park Orchards Family Practice

- Rockingham City Family Practice

- Sans Souci Medical Practice

- Templestowe District Medical Centre

- Wentworth Avenue Family Practice

- Wyong Family Practice

Clinics not listed are not impacted, “based on our current investigation”, the provider says.

Partnered Health has launched a dedicated support page with steps patients can take to protect their information.

Patients have been warned to be alert to suspicious emails, texts and phones calls, and told they should not click on links or open attachments in messages that look unusual or unexpected.

Passwords should also be strong and unique for all accounts.

The attack came five days after insurance giant Bupa agreed to buy Partnered Health Group and its national network of general practices, skin cancer, allied health and mental health clinics.

The acquisition, which is subject to ACCC and Foreign Investment Review Board approval, will included the Jobfit, Baseline Onsite, New View Psychology, NewPsych Psychology, and Australian EAP brands.