Scammers filled with their own type of Christmas spirit are gleefully eyeing chances to exploit the stressed and vulnerable this holiday season.
Netsafe chief executive Martin Cocker said some professional scammers could run multiple types of cons, tailoring their approach to different times of year.
It's now the season of package delivery swindles and holiday home scams, Cocker said.
He said people feeling financial, time and social pressures were at risk of getting distracted and suckered.
"It decreases the amount of time people have to be cautious and to review information.
"At Christmas you've got a lot of packages moving around and a lot of freight scams."
The huge expected surge has prompted NZ Post to deploy 200 more courier vans, 185 extra flights, and 350 more staff to deliver Christmas presents for New Zealanders.
Cocker said freight scams typically involved people being told a package was on the way and payment was needed to get the goods delivered.
He said the amounts requested were generally modest, perhaps something like $5, persuading victims to pay.
But freight scammers sometimes asked for credit card details, Cocker said. Those details could be repeatedly used to take more money from victims.
Holiday home scams were also common at Yuletide, Cocker said.
These scams exploited the stress and indecision accompanying last-minute holiday plans.
"You've all agreed as a family you're going to go to Queenstown but you've left it 'til the last minute. A lot of accommodation is gone."
But then, a new holiday home offer might emerge online, with the listing asking for an up-front payment to secure the place.
"They're totally false adverts," Cocker said. "You're under pressure. You're trying to meet your own requirements. It's that pressure that advantages the scammer."
Cocker said most of the scammers were based abroad but capable of feigning local knowledge.
"The internet provides you with just about everything you need. I can tell you right now what the weather is like where you are. I can tell you the things that have happened in your local region. I can sound like a local to you."
Scammers sometimes only had to fool a small minority of their targets to cash in. The Christmas season con artists also had minimal expenses.
"It's 100 per cent profit margin and they can spend all the time they like preparing the scam."
Other scams include business email compromise (BEC), where criminals can use hacking, phishing or malware to trick victims into transferring money.
Some BEC attacks involve impersonating a supplier and requesting urgent payment from companies.
Team New Zealand was reportedly the victim of such a scam last year, when a fraudster using a similar email address to a legitimate business persuaded Team NZ to hand over $2.8 million.
Although many foreign scammers got away with fraud, Cocker said international law enforcement had improved in recent years.
One example of global law enforcement co-operation is Interpol's Operation First Light, which tackles transnational phone scams and business email compromise (BEC).
Operation First Light has uncovered money transfers worth millions from a Hungarian-based BEC company to Hong Kong bank accounts.
The Interpol financial crime investigation has also disrupted scammers in China, South Korea and Germany.
Cyber-enabled attacks on retailers and other businesses reliant on Christmas spending could be devastating.
Cocker said companies attacked or held for ransom at the busiest time of year were in theory more likely to pay ransoms.
On its website, Netsafe had more advice for Kiwis on how to shop online safely - and hopefully, dodge the holiday scams.