# Skill Signature Registry

---

## Header

| Field | Value |
|-------|-------|
| **Report type** | registry |
| **Target** | ~/.claude/skills (local registry) |
| **Date** | 2026-05-05 |
| **Mode** | scan |
| **Version** | llm-security v7.4.0 |
| **Scope** | skill-signature fingerprint registry |
| **Triggered by** | /security registry scan |

---

## Risk Dashboard

| Metric | Value |
|--------|-------|
| **Risk Score** | 18/100 |
| **Risk Band** | Medium |
| **Grade** | B |
| **Verdict** | WARNING |

| Severity | Count |
|----------|------:|
| Critical | 0 |
| High | 1 |
| Medium | 2 |
| Low | 2 |
| Info | 5 |
| **Total** | **10** |

**Verdict rationale:** 1 HIGH on a known-malicious skill fingerprint match (`malicious-pdf-helper@1.0.0`). 2 MEDIUM on signature drift for previously-trusted skills.

---

## Registry Stats

| Metric | Value |
|--------|------:|
| **Skills tracked** | 87 |
| **Known-good fingerprints** | 79 |
| **Known-bad fingerprints** | 4 |
| **Unknown fingerprints** | 4 |
| **Drift events (30d)** | 7 |
| **Registry file** | reports/skill-registry.json |

---

## Signature Table

| Skill | Source | Fingerprint (SHA-256, 8-hex) | Status | First seen |
|-------|--------|------------------------------|--------|-----------|
| pdf-helper | builtin | a8f3e21d | known-good | 2026-01-12 |
| story | user | 4c2b89f0 | known-good | 2026-02-08 |
| malicious-pdf-helper | npm | 7e91d3a4 | KNOWN-BAD | 2026-04-22 |
| story-v2 | user | 9f1c2e8b | DRIFT (was 4c2b89f0) | 2026-05-04 |
| audit-helper | community | b3a7f29c | DRIFT (was c814e7a1) | 2026-05-03 |
| pptx | builtin | d7e4a1f3 | known-good | 2026-01-12 |
| capability-auditor | community | e2f9b483 | unknown (new) | 2026-05-05 |
| persona-creator | builtin | 1a4c8e07 | known-good | 2026-01-12 |

---

## Findings

### High

| ID | Category | Skill | File | Description | OWASP |
|----|----------|-------|------|-------------|-------|
| REG-001 | Known-bad | malicious-pdf-helper | ~/.claude/skills/malicious-pdf-helper/SKILL.md | Fingerprint matches 2026-04-22 advisory (data exfiltration via PDF metadata) | LLM05 |

### Medium

| ID | Category | Skill | File | Description | OWASP |
|----|----------|-------|------|-------------|-------|
| REG-002 | Drift | story-v2 | ~/.claude/skills/story-v2/SKILL.md | Fingerprint changed since registry — verify legitimacy | LLM05 |
| REG-003 | Drift | audit-helper | ~/.claude/skills/audit-helper/SKILL.md | Fingerprint changed since registry — verify legitimacy | LLM05 |

### Low

| ID | Category | Skill | File | Description | OWASP |
|----|----------|-------|------|-------------|-------|
| REG-004 | Unknown | capability-auditor | ~/.claude/skills/capability-auditor/SKILL.md | New community skill, no prior fingerprint — recommend manual review | — |
| REG-005 | Stale | unused-skill | ~/.claude/skills/unused-skill/SKILL.md | No invocations in 90 days — candidate for removal | — |

### Info

| ID | Category | Skill | File | Description | OWASP |
|----|----------|-------|------|-------------|-------|
| REG-006 | Coverage | (registry) | reports/skill-registry.json | 87 skills tracked across 4 sources (builtin/user/community/npm) | — |
| REG-007 | Coverage | (cache) | ~/.cache/llm-security/registry/ | Cache size: 412 KB | — |
| REG-008 | Coverage | (cache) | (TTL) | Registry cache TTL: 24h | — |
| REG-009 | Coverage | (cache) | (next sync) | 17h until next registry sync | — |
| REG-010 | History | (audit) | reports/registry-audit.jsonl | 7 drift events in last 30 days, all on community skills | — |

---

## Recommendations

1. **Immediate:** Disable or remove `malicious-pdf-helper` skill. Cross-reference with `~/.claude/skills/` and check if any agents reference it.
2. **High:** Investigate signature drift on `story-v2` and `audit-helper`. Compare against last-known-good fingerprint and re-register if legitimate update.
3. **Medium:** Manually review `capability-auditor` (new, unknown). Run `/security scan ~/.claude/skills/capability-auditor` for full analysis.
4. **Low:** Audit unused skills — `unused-skill` has had no invocations in 90d.

---

*Registry scan complete. 87 skills, 1 known-bad, 2 drift events.*
