On January 1, we detected a significant increase in activity from one of the web skimmer groups we’ve been tracking. During this time, we found their malicious skimming code (detected by Trend Micro as JS_OBFUS.C.) loaded on 277 e-commerce websites providing ticketing, touring, and flight booking services as well as self-hosted shopping cart websites from prominent cosmetic, healthcare, and apparel brands. Trend Micro’s machine learning and behavioral detection technologies proactively blocked the malicious code at the time of discovery (detected as Downloader.JS.TRX.XXJSE9EFF010).

https://blog.trendmicro.com/trendlabs-security-intelligence/new-magecart-attack-delivered-through-compromised-advertising-supply-chain/