Variant Scan

Q: What is a Claude Code skill and how does the Variant Scan skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Variant Scan is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Security category. Learn more at https://claudskills.com/learn/what-is-skill-md/.

Category: Security · Sub-category: appsec-tools · Last updated: 2026-08-01

Seed-diverse multi-pass find: run the same target through THREE independent find passes — blind, threat-model-first, and CVE/history-seeded — union the candidates with vote-counting, then hit each with a 3-skeptic adversarial verify panel (correctness / reachability / impact). This is the recall engine the real-OSS campaigns were run on; it complements /vuln-scan (single-pass focus-area fan-out) rather than replacing it. Use when asked to "run the three passes", "variant scan", "blind + threat-model + CVE-seeded", "find everything in <crate>", or when a target has known history (CVEs/RUSTSEC) worth seeding from. Read-only. Its dispositions are TRIAGE, not verdicts — every survivor still needs an independent PoC (see the discipline gate below).

Security AStatic scan found no risk patternsHow grading works ›

About this skill (catalog notes)

Variant Scan is published as a SKILL.md file in this catalog. The SKILL.md runs to about 866 words, in the catalog's typical mid-range.

License: Apache-2.0
Original author: scadastrangelove
Indexed lastmod: 2026-08-01
Catalog position: Security · appsec-tools
Indexed related skills: 10

How Variant Scan fits the catalog

Variant Scan sits in the Security category under the appsec-tools sub-topic in the ClaudSkills catalog. There are 10 related skills indexed alongside it; comparing a few before installing usually reveals which fits your workflow best.

These notes are auto-generated from features detected in the SKILL.md file and from this catalog's structure — they aren't part of the source repository.

From the source SKILL.md

Three seed-diverse find passes over one target, unioned, then adversarially verified. This is the workhorse that ran every real-OSS campaign (x509-parser, lopdf, zune-jpeg, object, gimli, httparse, quick-xml, miniz_oxide, ciborium, png/image, rmp-serde, ttf-parser, gitoxide). Until now it lived only as a scratchpad workflow script; this skill is its permanent home.

What this skill does

Variant Scan is a community-contributed Claude Code skill in the appsec-tools sub-category. It ships as a SKILL.md file that Claude Code auto-discovers under ~/.claude/skills/variant-scan/ and loads when your prompt matches the skill's trigger.

When to invoke it: Use when asked to "run the three passes", "variant scan", "blind + threat-model + CVE-seeded", "find everything in <crate>", or when a target has known history (CVEs/RUSTSEC) worth seeding from. Read-only.

Who uses this skill

The Variant Scan Claude Code skill is built for security engineers, penetration testers, DevSecOps practitioners, and development teams hardening codebases and infrastructure. It's part of ClaudSkills (also referred to as Claude Skills or Claude Code Skills) — the open community-curated registry of 174,000+ SKILL.md files for Anthropic's Claude Code agent and the wider Claude ecosystem (Claude API, Claude Agent SDK).

How to install

Free

Manual install (2 steps)

mkdir -p ~/.claude/skills/variant-scan
curl -L https://claudskills.com/skills/variant-scan/SKILL.md \
  -o ~/.claude/skills/variant-scan/SKILL.md

Or just download SKILL.md directly and drop it into ~/.claude/skills/variant-scan/. Claude Code auto-discovers it on next session.

Skills live at ~/.claude/skills/variant-scan/SKILL.md on macOS/Linux, or %USERPROFILE%\.claude\skills\variant-scan\SKILL.md on Windows. See the full install guide for step-by-step instructions.

📱 Install from your phone or desktop Telegram

Open @claudskills_bot on Telegram, tap Open Desktop App, and the desktop app installs this skill for you. Or share the bot link with a colleague — they get the same one-tap install. Learn more →

Pro

One-click install via the desktop app

The ClaudSkills desktop app installs any skill directly into ~/.claude/skills/ with one click — no terminal required. Pro starts at $9/mo or $149 lifetime.

Pro

For the full experience including quality scoring and one-click install features for each skill — upgrade to Pro.

See pricing → Download desktop app

Frequently asked questions

How do I install the Variant Scan Claude Code skill?

Install via the ClaudSkills desktop app (one click) or copy SKILL.md from the source repository to ~/.claude/skills/variant-scan/SKILL.md and restart Claude Code. Both flows are detailed at claudskills.com/install/.

What does the Variant Scan skill do?

Is this skill free to install?

Yes. ClaudSkills is an open registry — every skill keeps its source repository's license, and manual install via copy is free. ClaudSkills Pro ($9/mo, $79/yr, or $149 one-time) adds one-click install via the desktop app and a multi-signal Quality Score.

When should I use the Variant Scan skill?

Use Variant Scan when your Claude Code task falls under the Security category — specifically in the appsec tools area. Claude Code auto-discovers installed skills and invokes the right one based on the task description, so you can also ask Claude directly (e.g. "use Variant Scan" or describe the task and let Claude pick). Browse related skills at /category/security/.

What is a Claude Code skill and how does the Variant Scan skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Variant Scan is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Security category. Learn more at /learn/what-is-a-claude-skill/.

Attribution & license

Source: https://github.com/scadastrangelove/rust-in-peace/blob/94f6bf7680312f44b335663d1e258861c91d0bb6/.claude/skills/variant-scan/SKILL.md
License: Apache-2.0
Author: scadastrangelove

Cite this skill

If you reference this skill in a blog post, paper, or documentation, you can cite it as:

APA

scadastrangelove. (2026). Variant Scan [Claude Code skill]. ClaudSkills. https://claudskills.com/skills/variant-scan/

BibTeX

@misc{variant-scan-2026,
  author    = {scadastrangelove},
  title     = {Variant Scan [Claude Code skill]},
  year      = {2026},
  publisher = {ClaudSkills},
  url       = {https://claudskills.com/skills/variant-scan/}
}

Embed this skill

Promote, attribute, or link this skill from your own README, blog post, or documentation. All three snippets are free to use — no sign-up, no API key. More distribution surfaces →

Badge

[![ClaudSkills](https://claudskills.com/badge/variant-scan.svg)](https://claudskills.com/skills/variant-scan/?utm_source=badge&utm_medium=readme&utm_campaign=skill_badge)

Security scan

Grade A · scanned 2026-08-02 — free static scan against the OWASP Agentic Skills Top 10.

The scan flagged 1 of 10 categories (filesystem), including lower-severity patterns. Patterns shown inside code fences are weighted as examples rather than instructions — read the grading methodology for what this does and does not guarantee.

✓ Prompt injection
✓ Data exfiltration
✓ Supply chain
✓ Reverse shell
✓ Credentials
✓ Execution
⚠ Filesystem
✓ Persistence
✓ Obfuscation
✓ Network

Show this grade on your repo (click to copy):

[![Security: A](https://img.shields.io/badge/Security-A-2e7d32)](https://claudskills.com/skills/variant-scan/#security)

More Security skills

Browse all Security skills in the ClaudSkills registry, or explore these other picks from the same category:

Browse all Security skills → Top 100 skills

Part of ClaudSkills — the open registry for Claude Skills & Claude Code Skills. · What's New · Install guide · About · llms.txt

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