Waikato DHB is still scrambling to get back online following a ransomware attack that crashed its computers and phones.
Five hospitals in the region have had their second day without IT systems - with some elective surgeries postponed and outpatient clinics reduced.
Doctors are reverting to whiteboards and hard copy records to continue treating patients.
The rest of the public healthcare system is on high alert following the security breach.
Government cyber security agency CERT has seen an increasing number of attempts to hack systems for pay-off this year.
Professor Dave Parry from AUT's Department of computer science talks to Lisa Owen.
