Supermarket chain Tesco has warned its customers about a scam that has spread on Facebook, claiming that attending an event on the social network can will earn them a free £250 gift voucher.
In a posting on its Facebook wall, Tesco has said that websites and online adverts promising free Tesco vouchers "are a scam and nothing to do with Tesco."
WARNING: Any adverts, websites or Facebook pages offering 'first 100,000 attendants get a Free £250 Tesco Voucher' are a scam and nothing to do with Tesco. For everyone's online safety we ask you not to follow any links.
A quick search on Facebook reveals that thousands of shoppers have been fooled by the scam, and joined bogus events on the social network. At the time of writing, these have not been shut down by Facebook's security team and still pose a risk to unsuspecting users.
Tesco customers are being tricked into believing that they must join the Facebook event pages and follow a series of instructions to qualify for the £250 gift voucher.
Of course, following the instructions on the bogus event pages does not garner you a gift card. Instead, you are helping earn money for the scammers by driving more traffic towards their online surveys and granting them permission to post messages from your Facebook page.
If you're one of the many people who fell for this scam, please check your Facebook page to ensure that you are not spreading any messages to your online friends and ensure that you have revoked any Facebook applications, events and "like"d pages that you are uncomfortable with.
If you use Facebook and want to get an early warning about the latest attacks, you should join the Sophos Facebook page where we have a thriving community of over 150,000 people.Follow @gcluley