A Melbourne hospital has fallen victim to a cyberattack, with the data of about 15,000 patients impacted.

Melbourne Heart Group, a specialist cardiology unit in Cabrini Hospital in Melbourne’s south-east, was targeted by a ransomware attack which encrypted thousand of files.

According to a report in The Age, Melbourne Heart Group has been unable to access this data for about three weeks.

According to the report, the hackers demanded a ransom be paid in cryptocurrency for the files to be decrypted.

This was reportedly paid, but some have the files have not been recovered, The Age reported.

The files contain personal details and sensitive medical data, leading to fears for potential identity theft.

Toyota Australia was also attacked this week. Image: Supplied

The Australian Cyber Security Centre is now working with the hospital, while the Australian Federal Police has also been briefed.

Cabrini Hospital is an 832-bed not-for-profit hospital run by the Missionary Sisters of the Sacred Heart of Jesus.

A Melbourne Heart Group spokesperson said that none of its patients personal data had been leaked after it was unable to access it.

“This means that our patients’ information became inaccessible to anyone, including ourselves,” the spokesperson said.

“We have been assured that no patient’s privacy has been compromised in any way.”

The attack came in the same week that car manufacturing giant Toyota Australia said it was also the victim of an attempted breach.

“Toyota Australia can confirm it has been the victim of an attempted cyber attack,” a company spokesperson said.

“At this stage, we believe no private employee or customer data has been accessed.”

Attention has been heightened on cybersecurity recently after Prime Minister Scott Morrison revealed that the networks of Parliament House and the three major parties had been targeted as part of a “sophisticated” cyber attack.

The attack has been attributed to another nation-state, with authorities now investigating.