Security experts are warning of a scam on Facebook, which masquerades as a chance to get a free £250 ASOS voucher, but is instead an opportunity to earn money for scammers.
So how does it work, and what should you watch for?
The scamThe scam has been highlighted by independent security analyst Graham Cluley, who says this is the latest incarnation of a scam that has been around for a while. The scammers post a link, claiming "Get Free ASOS voucher Now (259 left)".
If you click on the link it will tell you to share the link with your own Facebook friends and make a favourable comment before you find out whether you have won a voucher.
As Cluley says on his blog: "Of course, ASOS isn't giving any way any such vouchers – and the promotion is nothing to do with them. Instead it's a ploy to trick users into taking online surveys which earn the scammers affiliate cash."
By the time you discover you've been scammed, you will have sent the link to your friends. This is how the scam multiplies - earning more and more cash for the scammers and spreading junk around Facebook.
More scamsIt's also worth bearing in mind that various forms of the Facebook scam exist. In December scammers were claiming to offer vouchers for Tesco, Asda and Primark. Often these scams are designed to trick you into completing a survey and earning cash for the scammers. However, some trick you into signing up for a premium rate service, and others contain viruses which will try to infect your computer if you follow the link.
If you see a link like this, you can check out whether it is real or not by visiting the Facebook page of the retailer themselves separately through a search (rather than clicking the link). If they are running an offer they will list it here, and sometimes if there's a scam doing the rounds they will post a warning on the site. Tesco did this in December, when it issued a scam warning and called on people to warn their friends.
You can also sign up to any number of Facebook security groups, including Cluley's own, which regularly issues scam warnings so you can keep abreast of the latest threats.
However, you'll go a long way if you heed the general rule of thumb that if something seems too good to be true it probably is, and if you receive an offer of something for nothing out of the blue then it's best to err on the side of caution.
After all, you have to ask yourself, given that ASOS is a phenomenally successful brand which is loved by millions of customers, why would they need to pay people £250 to share a positive comment?