supply-chain-overview

name	supply-chain-overview
description	Use when the engagement scope includes supply-chain attack simulation — typosquatted package publication, dependency confusion, GitHub Actions secret mining, internal mirror poisoning, OAuth-app impersonation, or vendor portal credential abuse.
metadata	{"subdomain":"supply-chain","when_to_use":"supply chain typosquat dependency confusion gh actions secret oauth app impersonation internal mirror poisoning vendor portal","tags":"supply-chain, typosquatting, dep-confusion, gh-actions, oauth-app","mitre_attack":"T1195, T1195.001, T1195.002, T1199, T1136, T1543"}

Supply Chain Operator Skill Catalog

Supply-chain attacks have grown 1,300% since 2020 per Decepticon's own ai-red-teaming.md. This catalog gives the agent the playbooks to simulate the most common patterns — all in a sandbox-isolated mode that publishes to a local mock registry by default and to a real one only with supply_chain_real_publish=true in ConOps.

Playbooks

Inline technique reference — not separately loadable skills. The entries below are summarized here for direct use; there is no separate SKILL.md to open for each. Do NOT call the skill loader on them — apply the technique with your tools using this summary and the Workflow in this file.

Technique	Use for
typo-name-gen	Generate typosquat candidates for a target package; reachability + popularity score
dep-confusion-probe	Check whether an internal package name is squat-able on PyPI / NPM / RubyGems / NuGet
post-install-script	Author + sandboxed publish of a benign post-install probe
gh-actions-fork-pr	Fork-PR secret mining; pull_request_target misconfiguration scan
oauth-app-impersonation	Lookalike OAuth app + scope-creep social engineering
internal-mirror-poison	Verdaccio / Artifactory / Nexus index manipulation
sbom-divergence	Audit SBOM vs actual installed packages for drift
vendor-portal-creds	SaaS vendor admin portal credential abuse paths

Dry-run mode

All publish-mode skills accept a --dry-run flag that:

1. Generates the typosquat package contents in /workspace/typo-pkg/.
2. Builds the artifact (.tar.gz, .tgz, etc.) without uploading.
3. Computes the "hit probability" via the target package's historical download counts + Levenshtein distance.
4. Reports the artifact location + hit probability for human review.

Real publish requires both supply_chain_real_publish=true in ConOps AND operator HITL approval at the moment of publish. Defense in depth.

GitHub Actions attack surface

Most rewarding attack class in 2024-2026. Common misconfigurations:

• pull_request_target with actions/checkout of ${{ github.event.pull_request.head.sha }} → fork PRs run with target-repo secrets.
• workflow_run triggers reading inputs without sanitization.
• ${{ github.event.pull_request.title }} interpolated into shell.
• Shared GITHUB_TOKEN with write scope on contents.

The gh-actions-fork-pr skill encodes the full enumeration: search the target org's workflows, identify exploitable patterns, build a PoC fork PR that exfiltrates secrets.* without modifying the workflow file itself (so the operator's PR doesn't look obviously malicious to a human reviewer).

Detection emission

For every simulated attack, the Detector agent produces:

• A Sigma rule for the SIEM (e.g., unusual npm install in CI logs, actions/checkout@ followed by secrets.* reference patterns).
• A GitHub Actions YAML linter rule for the customer's pre-merge checks.
• A SLSA attestation gap report.

Out of scope

Real-world publication that could harm third parties (other companies who consume the customer's internal packages). The dep-confusion-probe explicitly avoids this by checking name availability without uploading; the operator decides whether to follow through.