Australians are being warned to stay vigilant after a sophisticated scam involving Woolworths hit Facebook over the weekend.

The scam says that ‘250 lucky customers’ will win a years free groceries by sharing and commenting on a ‘Woolworths Club’ post.

The image then shows boxes of groceries ready to be won.

Over 3,000 people have commented and shared the image, with one shopper saying ‘This is a very kind gesture of kindness. I could feed my big brood. Thanks Woolworths and Woolworths Rewards for your kindness.’

The scam has since been reported to ACCC Scamwatch and Woolworths.