Secure Package Installation

Comprehensive security-first package installation workflow with PKGBUILD analysis

Secure Package Installation

The install_package_secure tool provides a comprehensive security-first workflow for installing packages on Arch Linux. It automatically checks both official repositories and the AUR, performing multiple security analyses before proceeding with installation.

Features

• Official Repos Priority - Always checks official repositories first (safer)
• Metadata Trust Analysis - Evaluates package votes, maintainer status, age, and maintenance
• PKGBUILD Security Scan - Detects dangerous commands, obfuscation, malware, crypto miners, rootkits
• Auto-blocking - Refuses to install packages with critical security issues
• AUR Helper Detection - Automatically uses paru (preferred) or yay
• No Confirmation - Uses --noconfirm flag for automated installations (only if security checks pass)

Installation Workflow

Security Checks

Metadata Trust Analysis

Evaluates package reliability through multiple signals:

Factor	Impact	Scoring
Package Votes	Community validation (higher = more trusted)	+5 per vote
Maintainer Status	Orphaned packages flagged as high risk	-30 if orphaned
Update Frequency	Out-of-date or abandoned packages detected	-20 if stale
Package Age	Very new packages flagged for review	-10 if < 30 days
Trust Score	Final 0-100 rating	70+ = Trusted, <30 = Untrusted

PKGBUILD Security Analysis

Static analysis detects common attack patterns:

🚨 Red Flags (Auto-blocking)

These patterns trigger immediate installation block:

- rm -rf /              # Destructive filesystem operations
- dd                    # Disk overwriting attacks
- :(){ :|:& };:         # Fork bombs
- /dev/tcp/             # Reverse shells
- nc -e                 # Netcat backdoors
- curl|sh, wget|sh      # Pipe-to-shell execution
- xmrig, minerd         # Crypto miners
- chattr +i, LD_PRELOAD # Rootkit techniques

⚠️ Warnings (Manual review recommended)

These patterns suggest suspicious behavior but allow installation:

- Base64 encoding/decoding
- eval usage
- World-writable permissions (chmod 777)
- Silent downloads
- systemd service manipulation
- Kernel module loading

Risk Score Calculation

Risk Score = (red_flags × 50) + (warnings × 5)
Scale: 0-100 (0 = safe, 100 = dangerous)

Usage

Via MCP Tool

Call the install_package_secure tool with a package name:

{
  "name": "install_package_secure",
  "arguments": {
    "package_name": "heynote"
  }
}

Response Format

{
  "package": "heynote",
  "installed": true,
  "is_official": false,
  "aur_helper": "paru",
  "messages": [
    "🔍 Checking official repositories first...",
    "⚠️  Package not in official repos - checking AUR...",
    "📦 Found in AUR: heynote v1.8.0",
    "🔍 Analyzing package metadata (votes, maintainer, age)...",
    "📊 Trust Score: 75/100",
    "   ✓ TRUSTED - Package has good community validation and maintenance",
    "🔍 Fetching PKGBUILD for security analysis...",
    "✓ PKGBUILD fetched (2453 bytes)",
    "🛡️  Analyzing PKGBUILD for security threats...",
    "🛡️  Risk Score: 15/100",
    "   ✓ SAFE - No critical issues detected. Standard review still recommended.",
    "   ⚠️  3 warnings found",
    "🔧 Checking for AUR helper...",
    "✓ Using AUR helper: paru",
    "📦 Installing heynote via paru (no confirmation)...",
    "✓ Successfully installed heynote from AUR"
  ],
  "security_checks": {
    "metadata_analysis": {
      "trust_score": 75,
      "recommendation": "✓ TRUSTED - Package has good community validation and maintenance",
      "risk_factors": [],
      "trust_indicators": [
        {
          "category": "popularity",
          "indicator": "Moderate vote count (42) - some community validation"
        }
      ]
    },
    "pkgbuild_analysis": {
      "safe": true,
      "risk_score": 15,
      "recommendation": "✓ SAFE - No critical issues detected. Standard review still recommended.",
      "red_flags": [],
      "warnings": [
        {
          "line": 23,
          "issue": "Network: silent download detected",
          "severity": "WARNING"
        }
      ]
    },
    "decision": "INSTALLED"
  }
}

Decision Outcomes

Decision	Meaning
INSTALLED	Package successfully installed
BLOCKED	Installation blocked due to critical security issues
REVIEW_RECOMMENDED	High risk warnings, manual review suggested
NO_HELPER	No AUR helper found (paru/yay)
INSTALL_FAILED	Installation command failed
INSTALL_ERROR	Exception during installation

Requirements

• Arch Linux system
• sudo access (for installation)
• AUR Helper: paru (recommended) or yay
  • Install paru: Follow instructions at https://github.com/Morganamilo/paru
  • Install yay: Follow instructions at https://github.com/Jguer/yay

Examples

Example 1: Official Package (Safe)

install_package_secure("firefox")

Result: ✓ Installed directly via pacman --noconfirm

Example 2: Trusted AUR Package

install_package_secure("yay")

Result:

• Trust Score: 95/100
• Risk Score: 5/100
• ✓ Installed via paru/yay

Example 3: Suspicious AUR Package

install_package_secure("suspicious-miner")

Result:

• Trust Score: 20/100 (orphaned, 0 votes)
• Risk Score: 100/100 (crypto miner detected)
• ❌ BLOCKED - Installation refused

Security Best Practices

1. Always review the output - Read the security analysis messages
2. Verify trust score - Packages with <50 trust score need extra caution
3. Check warnings - Even “safe” packages may have warnings to review
4. Update regularly - Keep AUR helper and pacman up to date
5. Use official repos when possible - The tool automatically prefers them

Limitations

• Requires Arch Linux (uses pacman/AUR)
• Needs sudo access for installation
• Requires AUR helper for AUR packages
• Cannot detect all malicious patterns (sophisticated obfuscation may bypass checks)
• Static analysis only (doesn’t execute code)

Debugging

Enable debug logs:

import logging
logging.getLogger("arch_ops_server").setLevel(logging.DEBUG)

Check installation output in the response:

{
  "install_output": "...",
  "install_errors": "..."
}

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