A new report details how the bedding sites MyPillow.com and Amerisleep.com were targeted with MageCart attacks. These types of attacks are called MageCart and have affected a large amount of well known online retailers such as NewEgg, TicketMaster, OXO, and British Airways. One of the biggest threats facing online retailers are malicious scripts that attackers add to checkout pages in order to steal customer payment information. This data is then sent to a remote server where the attackers can retrieve it.
Source: https://www.bleepingcomputer.com/news/security/payment-card-thieves-slip-into-mypillow-and-amerisleep-bedding-sites/