dependency-confusion

dependency-confusion is a skill for Claude Code, Codex from DorianGallo/hack-skills-local. It costs 56 tokens per session (2,356 once invoked), scanned A, a copy of dependency-confusion, MIT.

A supply-chain security guide for dependency confusion, where a package manager installs an attacker-controlled public package instead of an internal one.

In plain words
What is it for?
Reviewing npm, pip, RubyGems, Maven, Composer, and Docker manifests, lockfiles, registry order, package-name leaks, and authorized red-team exercises.
Why use it?
It helps find situations where package names, version ranges, or registry settings could let malicious install scripts run in builds or CI.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Reviewing npm, pip, RubyGems, Maven, Composer, and Docker manifests, lockfiles, registry order, package-name leaks, and authorized red-team exercises.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/doriangallo/hack-skills-local/dependency-confusion
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add DorianGallo/hack-skills-local --skill dependency-confusion
Clone the repo
git clone --depth 1 https://github.com/DorianGallo/hack-skills-local

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for dependency-confusion

README.md
[![agentmods](https://agentmods.dev/badge/skills/doriangallo/hack-skills-local/dependency-confusion/github.svg)](https://agentmods.dev/skills/doriangallo/hack-skills-local/dependency-confusion)
Your own site
<a href="https://agentmods.dev/skills/doriangallo/hack-skills-local/dependency-confusion"><img src="https://agentmods.dev/badge/skills/doriangallo/hack-skills-local/dependency-confusion/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for dependency-confusion

Your own site · 80×15
<a href="https://agentmods.dev/skills/doriangallo/hack-skills-local/dependency-confusion"><img src="https://agentmods.dev/badge/skills/doriangallo/hack-skills-local/dependency-confusion.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 56 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,356 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe.
Origin 100% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00056 $0.02356
Opus 5 $0.00028 $0.01178
Sonnet 5 $0.00011 $0.00471
Haiku 4.5 $0.00006 $0.00236

Measured 10d ago against content hash 8da1209f3125, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

dependency-confusion scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 10d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

# curl "https://search.maven.org/solrsearch/select?q=g:com.example+AND+a:internal-lib&rows=1&wt=json"
Origin

This is a copy

100% identical to dependency-confusion — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

skills/dependency-confusion/SKILL.md · 179 lines

How it starts

The opening of the file, as written. The whole thing — 179 lines — stays where its author put it; the contents beside it link to each section on GitHub.

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.

Routing note: if the task comes from supply-chain, repository exposure, or CI-build recon, first use recon-for-sec to list internal package names and possible public-registry collisions.


1. CORE CONCEPT

  1. Private packages: An organization ships libraries only on an internal registry (or under conventions that imply “ours”), e.g. a scoped name like @org-scope/internal-utils or an unscoped name such as acme-billing-sdk.
  2. Attacker squats the name: The same package name is published on a public registry (npmjs, PyPI, RubyGems, etc.).
  3. Resolver preference: Many setups resolve highest matching version across all configured indexes (or merge metadata), so a public 9.9.9 can beat a private 1.2.3 if ranges allow.
  4. Execution: Package managers run lifecycle scripts (npm preinstall/postinstall, setuptools entry points, etc.) → attacker code runs on developer laptops, CI, or production image builds.

Read the full file on GitHub · 179 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 10d ago First seen · 179 lines · 56 tokens per session scan A 8da1209f3125

Subscribe to this mod's changes

dependency-confusion is a skill published in the GitHub repository DorianGallo/hack-skills-local (5 stars, last pushed 3mo ago), licensed MIT. It adds 56 tokens to every session and 2,356 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). It is 100% identical to dependency-confusion, differing in 0 lines, and is treated as a copy.

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