New Zealand's health network battles against cyber assaults every day, officials have confirmed after a major attack led surgeries to be postponed at all Waikato public hospitals this week.
The Ministry of Health also said Tuesday's attack - which brought the Waikato District Health Board's entire IT system down - did not appear linked to another major assault on Ireland's health network recently.
The Waikato DHB has said it will not be able to fix its IT network until the weekend after Monday's attack disrupted emails, phone lines and other services.
Waikato DHB chief executive Kevin Snee earlier told news outlet RNZ the attack appeared to enter the health provider's network's system through an email attachment.
The Ministry of Health said it was now working with the DHB and National Cyber Security Centre as well as an "external specialist cyber security company" to recover from the attack.
And it appeared Tuesday's attack was unlikely to be the last major attack New Zealand's hospitals would face.
"All DHBS face cyber attacks in various forms daily," a Ministry of Health spokeswoman said.
"For security reasons, we will not be commenting on the response to the Waikato DHB incident in greater detail at this time."
Cyber attacks have been increasingly making headlines in recent years, including with the major ransomware attack on Ireland's health network last Friday and another ransomware attack that shut down a major fuel pipeline in the United States this week.
Against the growing cyber threat, the Ministry of Health said it had advised DHBs to ask staff to be particularly vigilant when using the internet.
"DHBs have been asked to go through their IT systems looking for patterns of a similar event," the ministry's spokeswoman said.
"They have also been asked to again check their anti-virus and other security systems are up to date and can protect their systems from a cyber attack."
"Staff are being urged to be extra careful clicking on links or attachments in emails, especially from people they don't know."
The Ministry's Data and Digital team had also encouraged DHBs to have a plan to deal with a cyber incident, the spokeswoman said.
DHBs should also have access to IT security expertise they could turn to for help, she said.
A Waikato DHB spokesperson earlier told the Herald they hoped to have everything up and running by the weekend.
The outage has impacted all hospitals under the Waikato DHB, including Waikato, Thames, Tokoroa, Te Kuiti and Taumarunui.
Outpatient clinics have been cancelled and families trying to reach their loved ones in hospital were urged to contact them on their personal mobile phones where possible due to the hospitals' phone lines also being down.
A significant number of elective surgeries had been postponed and access to patient notes was also limited but was expected to improve over the day, Snee told RNZ.
Former Waikato DHB member Dave Macpherson said they had been warned this could happen if they didn't keep up with what was needed to protect themselves from the type of attack.
"They always knew this sort of thing was likely to happen, but you would think they would have a plan B."