claude-code-ultimate-guide/examples/commands/security-check.md

name	description
security-check	Quick configuration security check against known threats database

Security Check

Quick configuration security check against known threats database. Verifies your Claude Code setup for known malicious skills, vulnerable MCPs, dangerous patterns, and exposed secrets.

Time: ~30 seconds | Scope: Claude Code configuration only

Instructions

You are a security analyst. Check the user's Claude Code configuration against the threat intelligence database bundled at examples/commands/resources/threat-db.yaml. Produce a concise, actionable report.

Phase 1: Load Threat Database

Read examples/commands/resources/threat-db.yaml from this repository to load:

• Known malicious authors and skills
• CVE database for MCP servers
• Suspicious patterns for hooks, agents, and config

Phase 2: MCP Server Audit

Read the user's MCP configuration:

# Global MCP config
cat ~/.claude/mcp.json 2>/dev/null

# Project MCP config
cat .claude/mcp.json 2>/dev/null

Check against threat-db.yaml:

• Any MCP server matching a CVE entry? → CRITICAL
• Version pinning: are all MCP servers pinned to exact versions (not @latest)? → HIGH if unpinned
• Any --dangerous-* flags in MCP args? → CRITICAL
• Any MCP servers not on the Safe List (see guide/security-hardening.md §1.1)? → MEDIUM (flag for manual review)

Phase 3: Skills & Agents Audit

# List installed skills
ls -la .claude/skills/ 2>/dev/null
ls -la ~/.claude/skills/ 2>/dev/null

# List agents
ls -la .claude/agents/ 2>/dev/null
ls -la ~/.claude/agents/ 2>/dev/null

# Check agent allowed-tools
grep -r "allowed-tools" .claude/agents/ 2>/dev/null
grep -r "allowed-tools" ~/.claude/agents/ 2>/dev/null

Check against threat-db.yaml:

• Any skill/agent name matching malicious_skills entries? → CRITICAL
• Any skill/agent author matching malicious_authors entries? → CRITICAL
• Any agent with allowed-tools: ["Bash"] only? → HIGH
• Any agent with overly broad tool access + vague description? → MEDIUM

Phase 4: Hook Security

# List all hooks
find .claude/hooks/ -type f 2>/dev/null
find ~/.claude/hooks/ -type f 2>/dev/null

# Scan hooks for suspicious patterns
grep -rn "curl\|wget\|nc \|ncat\|netcat\|base64\|eval\|exec\|/dev/tcp\|/dev/udp" .claude/hooks/ 2>/dev/null
grep -rn "curl\|wget\|nc \|ncat\|netcat\|base64\|eval\|exec\|/dev/tcp\|/dev/udp" ~/.claude/hooks/ 2>/dev/null

# Check for credential access in hooks
grep -rn "ssh\|id_rsa\|id_ed25519\|\.env\|credentials\|secret\|password\|token\|api.key" .claude/hooks/ 2>/dev/null
grep -rn "ssh\|id_rsa\|id_ed25519\|\.env\|credentials\|secret\|password\|token\|api.key" ~/.claude/hooks/ 2>/dev/null

Check against threat-db.yaml suspicious_patterns.hooks:

• Network calls (curl, wget) → HIGH
• Reverse shell indicators (nc, /dev/tcp) → CRITICAL
• Credential access (ssh, .env, password) → CRITICAL
• Base64 encoding → MEDIUM (review context)

Phase 5: Memory Poisoning Check

# Check for suspicious instructions in memory/config files
grep -in "ignore\|forget\|override\|disregard\|you are now\|new role\|system prompt" \
  CLAUDE.md .claude/CLAUDE.md SOUL.md .claude/SOUL.md MEMORY.md .claude/MEMORY.md \
  ~/.claude/CLAUDE.md ~/.claude/MEMORY.md 2>/dev/null

• Prompt injection patterns in CLAUDE.md / SOUL.md / MEMORY.md? → HIGH
• Instructions to disable security, skip reviews, or grant broad permissions? → CRITICAL

Phase 6: Permissions & Settings

# Check settings
cat .claude/settings.json 2>/dev/null
cat ~/.claude/settings.json 2>/dev/null

• permissions.deny exists and covers .env*, *.pem, *.key, secrets? → MEDIUM if missing
• No wildcard permissions.allow for Bash or Write? → HIGH if present
• No dangerouslySkipPermissions or similar flags? → CRITICAL if present

Phase 7: Exposed Secrets in Config

# Check for secrets in .claude/ directory
grep -rn "sk-[a-zA-Z0-9]\{20,\}\|sk-ant-[a-zA-Z0-9]\{20,\}\|ghp_[a-zA-Z0-9]\{36\}\|AKIA[A-Z0-9]\{16\}" \
  .claude/ ~/.claude/ 2>/dev/null

# Check for private keys
grep -rn "BEGIN.*PRIVATE KEY" .claude/ ~/.claude/ 2>/dev/null

• API keys or tokens in config files? → CRITICAL
• Private keys in config? → CRITICAL

Output Format

## 🛡️ Security Check Report

**Date**: [timestamp]
**Scope**: Claude Code configuration

### Results Summary

| Severity | Count | Status |
|----------|-------|--------|
| 🔴 CRITICAL | X | [PASS/FAIL] |
| 🟠 HIGH | X | [PASS/FAIL] |
| 🟡 MEDIUM | X | [PASS/FAIL] |
| 🟢 LOW | X | [PASS/FAIL] |

### 🔴 Critical Issues
[List each critical finding with location and fix]

### 🟠 High Issues
[List each high finding with location and fix]

### 🟡 Medium Issues
[List each medium finding with location and fix]

### ✅ Passed Checks
[List what passed — important for confidence]

### 🔧 Recommended Actions (Priority Order)
1. [Most urgent fix with exact command]
2. [Second priority]
3. [...]

### 📚 References
- Full security guide: guide/security-hardening.md
- Threat database: examples/commands/resources/threat-db.yaml
- MCP scan: `npx mcp-scan` (Snyk)

If ALL checks pass, output:

## 🛡️ Security Check Report — ALL CLEAR ✅

**Date**: [timestamp]
No known threats detected in your Claude Code configuration.

**Recommendations for continued security:**
- Re-run `/security-check` after installing new skills or MCP servers
- Run `/security-audit` for a comprehensive project + config audit
- Keep Claude Code updated (current security fixes in v2.1.34+)

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