An internet security watchdog is warning people carrying out financial transactions online that there has been a sudden surge in malware attacks.
Malware involves a person's device being taken over and fake invoices being sent to customers or a person's data being encrypted and held to ransom.
State cyber security agency CertNZ said there have been 1000 such attacks in the past two months.
Its deputy director, Declan Ingram, said the attacks from offshore are happening on a global scale.
One of the best protections is software which generates multiple passwords for various websites but only requires the user to remember one of them, Ingram said.
Earlier this month police warned landline users that there was an increased risk of phone scammers conning them out of thousands of dollars.
Three men in Auckland, aged in their 20s and 30s, have been charged in relation to alleged money laundering after an 84-year-old victim lost almost $10,000 after getting a phone call from someone pretending to be from Spark.