More than 4000 fake online shops have been taking advantage of the post-Christmas sales and discount season to steal customers’ personal information, researchers at Avast found.

These e-shops mimic famous fashion brands such as Converse, Guess, Kate Spade, Stussy, Toms, Ugg, and Zara to extort personal or payment information from users when they create a customer account or try to pay for an order.

The fake shops can appear credible with a high search ranking when related terms are searched for online, making it easier for consumers to fall for their tricks.

Avast said its products have protected more than 21,000 users from these scams this holiday season.

The company advised consumers to always check the legitimacy of shopping websites, especially during this period of discounts and tempting offers.