Scammers are luring users into clicking on a harmful link to make them participate in a competition which claims to be run by British Airways.
The fake post claims the airline is giving away Â£500 vouchers to celebrate its anniversary along with a picture of a code and what looks like a genuine British Airways logo.
But the url for the website – Britishairways.com-offer.wins - is really a malware site used to steal personal information from potential travellers.
Under the terms and privacy conditions it was specified that British Airways is neither "the organiser nor a sponsor of this website and has no business relationship with the organiser.”
A spokesperson for BA said: “We provide, and regularly update extensive guidance to our customers on how to spot, report and safeguard against fraudulent activity.
"We also immediately update ba.com to warn our customers about any particular examples of illegal activity targeting the public via social media."