Npm Supply Chain Security

npm-supply-chain-security

Description

Protect your JavaScript projects from npm supply chain attacks. Learn to identify malicious packages, implement trusted publishing, and use security heuristics to detect compromised dependencies.

Implementation

NPM supply chain attacks have become increasingly common, with recent incidents affecting packages with millions of weekly downloads. The Axios attack in March 2026 demonstrated how leaked long-lived npm tokens can be exploited to publish malicious dependencies.

Key Security Practices:

Trusted Publishing: Configure GitHub Actions workflows as the only authorized publishers to npm

Release Verification: Check for accompanying GitHub releases when new package versions are published

Dependency Monitoring: Watch for newly published dependencies in established packages

Token Management: Use short-lived, scoped tokens instead of long-lived global tokens

Red Flags for Malicious Packages:

New dependencies added to established packages

Versions published without corresponding GitHub releases

Freshly published dependency packages with suspicious names

Unusual code patterns or obfuscated implementations

Code Examples

Example 1: Configure Trusted Publishing

{
  "name": "your-package",
  "version": "1.0.0",
  "publishConfig": {
    "registry": "https://registry.npmjs.org/",
    "provenance": true
  },
  "scripts": {
    "release": "npm publish --provenance"
  }
}

Example 2: GitHub Actions Workflow for Trusted Publishing

name: Publish Package
on:
  release:
    types: [published]
jobs:
  publish:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      id-token: write  # Required for trusted publishing
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: '20'
          registry-url: 'https://registry.npmjs.org'
      - run: npm ci
      - run: npm publish --provenance
        env:
          NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}

Example 3: Security Heuristic Checker

import requests
import json
def check_package_release_heuristic(package_name, version):
    """Check if package version has corresponding GitHub release"""
    # Get package info from npm registry
    npm_url = f"https://registry.npmjs.org/{package_name}/{version}"
    npm_response = requests.get(npm_url)
    
    if npm_response.status_code != 200:
        return False, "Package version not found"
    
    npm_data = npm_response.json()
    repository = npm_data.get('repository', {}).get('url', '')
    
    if 'github.com' not in repository:
        return True, "Non-GitHub repository"  # Can't verify
    
    # Extract GitHub repo info
    repo_parts = repository.replace('https://github.com/', '').replace('.git', '').split('/')
    if len(repo_parts) != 2:
        return True, "Invalid repository format"
    
    owner, repo = repo_parts
    github_release_url = f"https://api.github.com/repos/{owner}/{repo}/releases/tags/v{version}"
    github_response = requests.get(github_release_url)
    
    if github_response.status_code == 200:
        return True, "GitHub release found"
    else:
        return False, "No corresponding GitHub release - potential red flag!"
Usage
safe, message = check_package_release_heuristic("axios", "1.14.1")
print(f"Security check: {safe} - {message}")

Example 4: Dependency Audit Script

const fs = require('fs');
const path = require('path');
function auditDependencies(packageJsonPath) {
    const packageJson = JSON.parse(fs.readFileSync(packageJsonPath, 'utf8'));
    const dependencies = {...packageJson.dependencies, ...packageJson.devDependencies};
    
    // Check for recently published packages (simplified)
    const suspiciousPatterns = [
        'crypto-js', 'plain-', 'simple-', 'basic-', 'core-'
    ];
    
    const suspiciousDeps = [];
    for (const [dep, version] of Object.entries(dependencies)) {
        // Check if dependency name matches suspicious patterns
        if (suspiciousPatterns.some(pattern => dep.includes(pattern))) {
            suspiciousDeps.push(dep);
        }
    }
    
    return suspiciousDeps;
}
// Usage
const suspicious = auditDependencies('./package.json');
if (suspicious.length > 0) {
    console.warn('Suspicious dependencies detected:', suspicious);
}

Dependencies

Python 3.8+ (for security scripts)

requests library

Node.js 18+ (for npm workflows)

GitHub CLI (optional, for automated verification)