fp-check
An agent skill by trailofbits, from trailofbits/skills. Tags: analysis, debugging, evaluation, security, validation.
What it does
Systematically verifies suspected security bugs to eliminate false positives, producing a TRUE POSITIVE or FALSE POSITIVE verdict with documented evidence for each. Use when asked whether a specific finding is real, exploitable, or a false positive, or to verify or validate a suspected vulnerability — not for hunting or discovering new bugs.
Install
With the skills CLI, which installs into Claude Code, Codex, Cursor and other agents:
npx skills add trailofbits/skills --skill fp-checkOr copy the skill folder into Claude Code's skills directory by hand (~/.claude/skills for every project, or .claude/skills inside one):
git clone --depth 1 https://github.com/trailofbits/skills
cp -r skills/plugins/fp-check/skills/fp-check ~/.claude/skills/fp-checkSafety box score
Not rated yet. A safety box score grades what a skill and its scripts can reach on the machine of whoever installs it, across eight categories from shell execution to secrets access. Anyone can request one from this page; it is saved for everyone. How the score works.
Source
- Repository
- trailofbits/skills (all skills from this repository)
- Path
- plugins/fp-check/skills/fp-check/SKILL.md
- Branch
- main
- Collection
- fp-check
- Updated
- 2026-09-19
Related skills
- post-patch-validation — Validates security patches with reproducible baseline-versus-patched evidence, including original exploits, root-cause variants, behavior preservation.
- audit-context-building — Understand a codebase before looking for bugs in it - what each function assumes, what it guarantees, and what it depends on elsewhere.
- c-review — Performs comprehensive C/C++ security review for memory corruption, integer overflows, race conditions, and platform-specific vulnerabilities.
- code-maturity-assessor — Systematic code maturity assessment using Trail of Bits' 9-category framework.
- constant-time-analysis — Detects timing side-channel vulnerabilities in cryptographic code.
- differential-review — Performs security-focused differential review of code changes.