If you have a mobile phone, you may have noticed a missed call from an unknown international number.
The Deputy Chief of the Australian Consumer and Competition Commission, Delia Rickard], says the ACCC has seen a dramatic increase in scam phone calls from international numbers.
"Australian phones are being flooded at the moment, with what we call 'wangiri' scams. And this is where you get a call from an overseas number, they ring once, hang up and what they want you to do is to call them back."
if the call is returned, the scammers try to keep people on the phone for as long as possible.
Technology expert Valens Quinn says they might play music, read a horoscope, or simply put people on hold.
"Well it's just like a 1300 number type of thing, so you get charged for the call. The longer the call is, the more you get charged. The scammers can basically set the cost per minute."
The ACCC has received 190 complaints about this kind of fraud since January.
But they say people don't always report it, so the actual numbers could be much higher.
Australians who've experienced them are not hard to find:
"I think we all have, haven't we? At some point or another. So yes, definitely."
"You always get them."
"Yes."
"Quite frequently. Like every few weeks."
"Yeah sometimes I get them from events or something and they ask me if I would like to do a survey."
"I've got like so many people calling me and they don't answer."
The ACCC's Delia Rickard believes migrants are more likely to get scammed.
"If you know people in the country that they're calling from, particularly if it's your home country and you've got family there, you're definitely going to be more at risk because you're going to look at that and hope that it's someone you're waiting to hear from and call back. So I do think that people of *CALD backgrounds are more at risk of this, just because they are likely to have more overseas connections."
So are telephone companies doing anything to curb the problem?
In an article on their website, Telstra warns customers against answering unknown international numbers, and suggests blocking unwanted numbers.
Optus encourages customers to report incidents to the ACCC's Scamwatch.
And while Vodafone says they actively block known scam numbers, they say there are limits to how much phone companies can do.
Vodaphone says "monitoring and blocking is ongoing because unfortunately as soon as one number is blocked, the fraudsters can switch to a different number."
But advice for consumers is pretty simple, says Valens Quinn.
"Well it happened to me the other week actually. I got a call from Cuba. I know I don't know anyone in Cuba, so I didn't answer it -- which is what you should do, don't answer the phone. Really it just depends on whether you know someone in that country. Most likely you probably don't, so just don't answer it."
Melbourne resident Utkarsh received a call from an overseas number two weeks back. He recalls that they were very professional and were asking for money by scaring him to get his passport cancelled.
He says, if you smell a little that its scam just hang up.
