Often on social media you’ll see a link saying something like “Buy bitcoin for 5% under market value. Save big!” This is a marketing trick to get you to visit and use their fake exchange.
If you visit any exchange site the very first thing you want to do is make sure it’s HTTPS secured and not HTTP. This means that the web traffic is encrypted and secured; if it’s just HTTP without the “S” that is a big red flag and means stay away.
Another red flag to look out for are fake exchanges that offer selling Bitcoin for PayPal. On these sites you’ll see a web form to enter your PayPal email and amount to sell. After submitting, you will be presented with a QR code to send your bitcoin to. But the money never arrives.
Most of these fake exchanges are here one day and gone the next. You will see them pop up but will quickly disappear, and then re-emerge with a different domain name later.