Scammers pretending to be from Microsoft conned thousands of dollars out of Kiwis last week, ringing up Ashburton residents and convincing them to hand over their credit card details.
At least two people fell for the ruse, in which they gave crooks access to their computers and paid hundreds of dollars for them to remove non-existent viruses.
"Fear's a very compelling way to sell anything, and that includes scams," NetSafe director Martin Cocker said on the Paul Henry programme this morning.
"There's a thing in a [computer running Microsoft Windows] called the Event Viewer, and to most people it makes no sense at all, so if your attention is drawn to that it's easy to believe there's something wrong when you see all the little flags in it."
This type of scam has been running for years, but Mr Cocker says it's an easy one to fall for if you're not computer-savvy.
"Most times you take your computer somewhere to be serviced, you have to pay for it – so in that regard, it's not necessarily [strange]," he says.
"These are all scams – nobody rings you and fixes your computer remotely like this, legitimately. They are all scams. But I guess for most people who have had their computer repaired, it's all a bit mysterious."
Newer types of computer scams are now starting to emerge. A particularly successful one has tricked company accountants into paying fake bills.
"It's easy to sort of fake internal emails between employees, and so we've seen a successful [scam] where the fake CEO emails one of the accountants… either got into the system and used the actual email, or just faked the email so it looks real, and then they ask the accountant to pay a bill – which is a fake bill – and the accountant duly follows, because we all do what our CEOs tell us," says Mr Cocker.
"It tends to be medium companies that are more likely to have slightly looser accounting practises."
An old scam that still seems to work involves paying a small amount of money to free up a much larger inheritance or lottery windfall. Mr Cocker's advice?
"That makes absolutely no sense at all. Don't pay."
More information on how to avoid computer scams is available on NetSafe's website.