An 88-year-old man who had nearly $50,000 siphoned out of his bank accounts has put aside his embarrassment to warn others about the scam.
Brian Cotter, who lives in a retirement home in Mt Maunganui, received a phone call just before lunchtime on Friday from someone claiming to work at Spark.
The man warned Cotter there had been thousands of people scammed by cyber-ransom attacks in New Zealand and Spark was checking the security of its fibre lines.
Unable to understand the supposed Spark technician, Cotter then spoke to the man's supervisor who was a "very smooth operator".
"They would say, you'll see a pop-up window soon - then there was one. I don't know how the hell they got into my computer, I never handed out any passwords or account numbers or anything," said Cotter.
Still suspicious, the pensioner tried to call Spark to verify what the men were saying - but was unable to reach an operator.
After several hours of speaking on the phone, Cotter was fed up and wanted to end the conversation.
However, they convinced him to leave the phone and computer switched on while he visited his neighbour, then had dinner.
"They promised to fix up all the bugs and install some free anti-virus software and so on," said Cotter.
"I'm such a mug."
He returned to find between $40,000 and $50,000 siphoned out of his accounts in several large transactions.
"I'm normally so careful. They must have put some sort of spyware on the computer," said Cotter.
"Some people would be too ashamed to talk about this. And I do feel shame. But I want to warn all the young people like me."
Cotter had his bank accounts suspended and will visit the offices in person tomorrow.
He questioned why he didn't receive a phone call or text message - known as two-factor authentication - from the banks to verify the large transactions.
One was $18,000, another for $12,000.
While banks often reimburse victims of fraud, they can decline to do so if they believe the customer was negligent.
The Banking Ombudsman last week highlighted a similar case in International Fraud Awareness Week where the disgruntled customer and the bank eventually resolved the matter.
"It is, however, a salutary reminder of the increasing sophistication of online scams and to be very suspicious of unsolicited calls offering help with banking or security."
A spokeswoman for Spark said there had been an increase in scammers cold calling people, pretending to be from well-known companies like Spark, or other telcos or banks.
"These fraudsters often monitor corporate activity and mimic their methods of communication, so it can be difficult for customers to tell the difference between what's genuine and fake."
Spark would never ask for personal details, she said, so if someone was suspicious about a phone call, she had some simple advice: Hang up.