A security researcher collected in a span of a few weeks over 1,000 domains infected with payment card skimmers, showing that the MageCart continues to be a prevalent threat that preys on insecure webshops. MageCart was first spotted over a decade ago by cybersecurity company RiskIQ but attacks have grown rampant over the past two years when big-name companies were hit. Most of the domains included in the research are already available from other sources, since this one-man effort took some time to reach a conclusion.
Source: https://www.bleepingcomputer.com/news/security/researcher-finds-1-236-websites-infected-with-credit-card-stealers/