Thousands of New Zealanders may have been caught up in a massive online data breach connected to Nitro PDF software.
The email addresses and hashed passwords of about 2.6 million users of Australian Nitro PDF software were published online.
New Zealand cyber security watchdog Cert said on Saturday it had contacted thousands of New Zealanders to warn them their online security may have been jeopardised by the massive online data breach.
It said among the email addresses used by people who registered for the software were more than 4000 that end with .nz.
Cert said it contacted those individuals, but other New Zealanders with email addresses ending in .com may be affected too.
Nitro PDF users were warned to change their Nitro PDF password immediately "to something long, strong and unique", and if the same password had been used for anything else to change that as well.