At least 18 skimmers or sniffers – scripts that copy credit card info at checkout – were identified since August 2017 on Reprint Mint photo store that prints covers of ESPN sports magazine and of the American military publication Stars and Stripes. Skimmer operators are extremely active, compromising hundreds of thousands of websites. One such threat actor alone managed to infect more than 40 web stores since October 2019. Authorities caught only three MageCart hackers that are part of a larger group that infected at least 571 stores since 2017.
Source: https://www.bleepingcomputer.com/news/security/18-sniffers-steal-payment-card-data-from-print-store-customers/