What it is
A supply chain attack targets not the site itself but a component it trusts — an npm package, a CDN-hosted script, a tag manager, or a widget. One compromised component executes with the full privileges of every page that loads it, making this vector exceptionally effective. In the web context it is the most common path to web skimming and formjacking.
Real-world examples
- British Airways (2018) — skimmer via a compromised modernizr.js.
- Polyfill.io incidents (2024) — mass compromise of a CDN script.
- Backdoored npm packages delivering a payload at build or runtime.
How ExploitShield detects it
Every host loaded by a monitored page is enriched (WHOIS, RDAP, AV, VirusTotal, blocklists), and every executed JS body is recorded and fingerprinted — so a compromised dependency is visible the moment it starts behaving differently from its baseline.