Dependency Confusion

This teaches Claude how to identify and test dependency confusion vulnerabilities across npm, pip, Maven, RubyGems, and other package ecosystems. It walks through the core mechanic (attacker publishes a higher version of an internal package name on a public registry), shows recon commands to check if names are squattable, and provides PoC patterns using DNS callbacks instead of destructive payloads. The guidance is red-team focused but includes defensive controls like scoped packages and lockfile enforcement. Load this when you're auditing manifests for supply chain risk or running authorized exercises against build pipelines. It pairs well with the recon-for-sec skill for initial package enumeration.

skills.sh installs: 3.8K
GitHub stars: 2.6K
last updated: Aug 21, 2026

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Install

$ npx -y skills add yaklang/hack-skills --skill dependency-confusion --agent claude-code

Installs into .claude/skills of the current project.

Files

SKILL: Dependency Confusion — Supply Chain Attack Playbook

AI LOAD INSTRUCTION: Expert dependency-confusion methodology. Covers how private package names leak, how public registries can win version resolution, ecosystem-specific pitfalls (npm scopes, pip extra indexes, Maven repo order), recon commands, non-destructive PoC patterns (callbacks, not data exfil), and defensive controls. Pair with supply-chain recon workflows when manifests or CI caches are in scope. Only use on systems and programs you are authorized to test.

0. QUICK START

What to look for first

Manifests listing package names that look internal (short unscoped names, org-specific tokens, product codenames) without a hard-private registry lock.
Evidence the same name might exist—or be squattable—on a public registry with a higher semver than the private feed publishes.
Lockfiles missing, stale, or not enforced in CI so install/build can drift toward public metadata.

Fast mental model: If the resolver can see both private and public indexes, and version ranges allow it, the “newest” matching version may be the attacker’s.

SKILL.md on GitHub

Details

Repository: github.com/yaklang/hack-skills
Categories: Testing & QA, DevOps & CI/CD, Git & Pull Requests, Code Review & Quality, Automation & Workflows, Python, Java & JVM, PHP & Laravel
First seen: Jun 3, 2026