PhantomRaven Exploits NPM's Unchecked HTTP URL Dependency Feature

Koi researchers detail PhantomRaven campaign exploiting npm's Remote Dynamic Dependencies feature that allows HTTP URLs as package dependencies. What's wild: this feature lets packages download code from HTTP endpoints during installation, bypassing security scanners since the malicious URL isn't in the code itself and isn't cached. The fake dependency runs automatically via preinstall hooks without user interaction. What's nasty: it scans for credentials and exfiltrates filesystem contents, and the fake packages use 'slopsquatting'—names matching incomplete package names that LLMs spit out (unused-import instead of eslint-plugin-unused-imports). Researchers discovered it by accident when they noticed traffic to the same HTTP domain across multiple packages. Started August 2025, npm removed some but 80 subsequent packages evaded detection. The attack gives attackers significantly more control since the download isn't cached and can serve different payloads per victim.