But when the 78-year-old showed her grandson the message he was immediately concerned.
"He said he hadn't entered anything and it was a scam," she said.
Duncan has shown the text message to staff at Countdown on Cameron Rd, who said she was the third person who had received the message and inquired in store.
Duncan said it was "scary" to think what could happen to people who were unaware this was a scam.
"Don't let those mongrels take what you've worked you're whole life for. It's so low," she said.
A Countdown spokesperson confirmed the text message about a $500 prize had nothing to do with the company.
"If ever someone has any doubt about the authenticity of a text or email they should always check with us before doing anything.
"If the offer seems too good to be true or sounds suspicious, unfortunately, it probably is, and we'd encourage customers to report illegal online activity to the police so they can investigate," the spokesperson said.
Netsafe's director of technology and partnerships, Sean Lyons, said the online safety organisation was aware of these types of scams.
"These links could click through to a scam website where scammers are looking to get payment or personal information, or it could potentially download malware on to the device," Lyons said.
He said people who received these texts or emails should delete them without clicking on any links.
In 2017 Kiwis reported a combined loss of $10.1 million dollars from online scams and fraud to Netsafe. The most substantial single loss reported was $480,000, and the average loss was $10,771.
A police media spokeswoman said police were not aware of this scam at this stage.
However, there were a number of scams circulating across New Zealand at the moment.
These included automated calls from someone with a Chinese accent claiming to be from courier company DHL or the Chinese Embassy, and automated calls claiming to be from the police threatening arrest for debts not paid to Inland Revenue.
Tips to protect yourself from scams:
•Don't respond to phone calls or contact about your computer asking for remote
access to fix it. No one will contact you out of the blue about a problem with your computer.
•Use good, strong passwords on your online accounts and don't tell anyone what they are. Legitimate organisations will never ask for your passwords. Use two-factor authentication on accounts where you can.
•Always keep your personal information secure. Think carefully before entering you details online, or giving them to someone.
•If someone offers you money or another offer, but you have to make a payment up front, ignore it. This is a common tactic of scammers.
•Use a good antivirus program and keep your software up to date. This will help to protect your device from someone trying to access it.
•Be wary of unusual payment requests. Scammers try to use payments that can't be traced such as pre-loaded debit cards, gift cards that can be used online, iTunes
cards or money transfer systems.
•If you're using a trusted trading or booking website or app, always complete the deal using the payment system on the platform.
•If you have lost money or given away personal information in a scam report it to Netsafe for advice www.netsafe.org.nz/report
Source: netsafe.orgnz
Countdown updated its online scams page whenever they become aware of an online scam. For more information visit: https://www.countdown.co.nz/about-us/consumer-information/countdown-scam-warning
