Code Review & Testing · IN-DEPTH PROFILE

Variant Analysis Skill

Systematic hunts for other instances of a known bug or vulnerability root cause.

View listed source ↗Installation guide ↓
Best for

Security researchers expanding a confirmed vulnerability class

What you get

Extract the root cause + Climb the abstraction ladder

Main limitation

Requires one validated bug in hand; it is not an initial discovery workflow.

First risk

Overbroad automated matches. Generalized patterns can generate many false positives or miss semantically different variants. Change one dimension at a time and manually review every reported candidate.

EVIDENCE FRESHNESS

Three checks, kept separate

A recent source check is not a runtime test or security audit.

Upstream sourceChecked 2026-09-23

Pinned revision · 32e34f81

Open pinned commit ↗
SkillSignal profileEditorial metadata

Updated 2026-09-23

Runtime & securityNot independently verified

Source review does not certify behavior or safety.

IN PLAIN ENGLISH

What it does—and when it fits

Variant Analysis is Trail of Bits' five-step workflow for finding other manifestations of a known bug root cause. It starts from an exact match, generalizes one dimension at a time, stops when noise dominates, and triages candidates with severity and prevention guidance.

This is aimed at Security researchers expanding a confirmed vulnerability class. Compare the examples below with your task, then review the limitations, permissions, and risks before installing.

What you get
  • Extract the root causeDescribe why the known instance is wrong and where variants may hide.
  • Climb the abstraction ladderCalibrate an exact match, then broaden one element per iteration.
  • Triage and preventSeparate true variants from look-alikes and propose a CI rule.
What makes it different
  • Prevents broad searches from drifting away from the known root cause.
  • Supports both simple search and CodeQL or Semgrep pattern families.
Community signalNo attributed third-party rating yet

No verified review text is in the current dataset. Use the linked source for the latest discussion.

Read the source note ↗

INSTALL BY AGENT

Choose your Agent

Paths come from official Agent docs or the universal installer behind skills.sh. Compatibility still follows this Skill's record.

Native

This Skill's current record explicitly names this Agent. Still inspect scripts, permissions, and external dependencies first.

Project install (recommended)
npx skills add trailofbits/skills --skill variant-analysis --agent claude-code
Personal install
npx skills add trailofbits/skills --skill variant-analysis --agent claude-code -g

Project install stays with this repository for team sharing. Personal install adds -g and works across repositories.

View install paths
Project path.claude/skills/variant-analysis/
Personal path~/.claude/skills/variant-analysis/
Official agent docs

Claude Code discovers custom Skill folders automatically at project or personal scope.

View path evidence ↗

TYPICAL WORKFLOW

A practical workflow

01

Extract the root cause

Describe why the known instance is wrong and where variants may hide.

02

Climb the abstraction ladder

Calibrate an exact match, then broaden one element per iteration.

03

Triage and prevent

Separate true variants from look-alikes and propose a CI rule.

THE TRADEOFFS

Advantages and tradeoffs

Notable strengths

  1. Prevents broad searches from drifting away from the known root cause.
  2. Supports both simple search and CodeQL or Semgrep pattern families.

Limitations

  1. Requires one validated bug in hand; it is not an initial discovery workflow.
  2. The stop-at-noise heuristic and final triage still depend on expert judgment.

COMPARE THE TRADEOFF

Consider these close alternatives

These are deterministic nearby candidates, not paid placements or a universal ranking. Open the full profile before choosing.

01

Same job family · native to Claude Code

frontend-design

Design constraints that push generated interfaces beyond generic AI UI.
Tradeoff to check
Aesthetic judgments remain subjective and still need stakeholder review.
First risk
Style over function · Medium
Source state
Pinned · 34040c9c
Open frontend-design profile ↗
02

Same job family · native to Claude Code

mcp-builder

Plan, implement, and evaluate high-quality MCP servers in Python or TypeScript.
Tradeoff to check
The guide cannot replace current MCP SDK or target-API documentation.
First risk
Overpowered external-service tools · High
Source state
Pinned · 34040c9c
Open mcp-builder profile ↗
03

Same job family · native to Claude Code

skill-creator

Create, improve, and benchmark Agent Skills with trigger tests and comparative evaluation.
Tradeoff to check
Meaningful benchmarks require representative prompts, repeat runs, and careful human judgment.
First risk
Untrusted evaluation prompts and artifacts · High
Source state
Pinned · 34040c9c
Open skill-creator profile ↗
Compare more in the directory →

BEST FIT

Who it is for

→

Security researchers expanding a confirmed vulnerability class

→

Maintainers checking whether one logic bug repeats elsewhere

BEFORE YOU USE IT

Risks to review before use

Medium

Overbroad automated matches

Generalized patterns can generate many false positives or miss semantically different variants. Change one dimension at a time and manually review every reported candidate.

SECURITY

What the permission profile means

  • Keep candidate reports scoped to the authorized codebase.
  • Do not publish exploit details before affected variants are remediated.

Not a security certification. External ratings are attributed references. SkillSignal has not independently executed or security-reviewed this Skill.

COMMON QUESTIONS

Variant Analysis Skill FAQ

What is the Variant Analysis Skill?

Systematic hunts for other instances of a known bug or vulnerability root cause. Variant Analysis is Trail of Bits' five-step workflow for finding other manifestations of a known bug root cause. It starts from an exact match, generalizes one dimension at a time, stops when noise dominates, and triages candidates with severity and prevention guidance.

How do I install the Variant Analysis Skill?

Open and review the listed source, choose the project or personal path for your Agent, then verify the first run in a controlled project. Open the pinned commit and read the current SKILL.md.

Is the Variant Analysis Skill safe to use?

SkillSignal checked the source on 2026-09-23, but that is not a runtime test or security certification. Review the “Overbroad automated matches” risk first and begin with the least access required.

INSIDE THE PACKAGE

Indexed files

SKILL.mdUpstream package contentSource-linked
references/Upstream package contentSource-linked
resources/codeql/Upstream package contentSource-linked
resources/semgrep/Upstream package contentSource-linked

TAGS

variant-analysisroot-causecode-search

Original SkillSignal editorial profile grounded in Trail of Bits commit 32e34f81, checked 2026-09-23; not independently executed or security-certified.