MAGECART and Claude Code Security frame a clear boundary in modern web security: Magecart-style attacks live outside the merchant’s codebase and execute at runtime in the shopper’s browser, often via compromised third‑party assets. A Magecart skimmer recently found in the wild hid its payload inside a favicon’s EXIF metadata, never touching the merchant’s source code or repository and exfiltrating data directly from the shopper at checkout.
The article argues that Claude Code Security, a static analysis tool designed to scan codebases, cannot see payloads buried in third‑party scripts or binary assets that lie outside the repository, nor assess attacker‑controlled domains that only appear at runtime. It stresses a four‑part pattern for such attacks: the initial loader looks benign, the payload hides in binary image metadata, exfiltration occurs in the browser, and nothing touches the merchant’s own repo.
Reflectiz frames runtime monitoring as essential to see what runs in users’ browsers, while static analysis and supply‑chain governance help reduce the attack surface, highlighting the need for a defence‑in‑depth approach. according to Reflectiz