Woolworths is warning Australians about a fake customer satisfaction survey which promises a $400 voucher.
The survey is a "phishing" scam designed by cybercriminals to collect personal information such as banking details, the supermarket chain says in an alert on its website.
The survey, which is circulating via email and Facebook, uses the Woolworths name and logo and promises a "free $400, $150 or $100" voucher as a reward.
The Australian Competition and Consumer Commission (ACCC) says it has received 140 other complaints about the scam since the beginning of the month.
Victims of a similar scam last year lost up to $1000 or were subscribed to premium SMS services which charge for every text received.
Vouchers are a legitimate marketing tool, meaning it is easy to get caught out by a fake one, says ACCC deputy chair Delia Rickard.
She advises the public never to trust surveys linked from social networking sites, even if they are recommended by friends.
"If you see one of these surveys, call the business' official customer service line before starting it.
"Don't rely on the links or numbers provided on the offer as this can link to a fake website or even a fake call centre."