About PMG

​

Architecture Overview

​

Workflow 1: Direct Package Installation

npm install express
pip install requests
pnpm add lodash

1. Command Interception: PMG intercepts the package manager command
2. Dependency Resolution: PMG resolves all transitive dependencies for the requested package
3. Threat Analysis: All packages in the dependency tree are analyzed for malware
4. Installation Decision: Clean packages proceed to installation, malicious packages are blocked

​

Workflow 2: Manifest File Installation

npm install          # Uses package-lock.json/pnpm-lock.yaml
pip install -r requirements.txt

• Lockfile Analysis: Dependencies are already resolved in lockfiles (package-lock.json, pnpm-lock.yaml)
• Direct Analysis: PMG analyzes the pre-resolved dependency list
• No Resolution Needed: Skip dependency resolution step

• Manual Resolution: Dependencies are NOT pre-resolved in requirements.txt
• Dependency Resolution: PMG must resolve transitive dependencies for each package
• Full Analysis: Analyze all resolved packages in the dependency tree

​

Core Technical Components

​

1. Command Interception Layer

# After pmg setup, these commands are automatically protected:
npm install express        #  Clean package - installs normally
npm install malicious-pkg  #  Blocked - malicious package detected

• Shell alias creation for transparent command wrapping
• Cross-shell compatibility (bash, zsh, fish)
• Argument parsing and forwarding to maintain compatibility

​

2. Dependency Resolution Engine

​

Strategy 1: Direct Package Installation Resolution

Your Package Request: express@^4.18.0
├── PMG Resolves Transitive Dependencies
│   ├── accepts@~1.3.8 (Clean)
│   ├── array-flatten@1.1.1 (Clean)
│   ├── body-parser@1.20.1 (Clean)
│   │   ├── bytes@3.1.2 (Clean)
│   │   ├── content-type@~1.0.4 (Clean)
│   │   └── debug@2.6.9 (Malicious - BLOCKED!)
│   └── cookie-signature@1.0.6 (Clean)
└── All packages analyzed before installation

• PMG queries package registries to build complete dependency tree
• Applies semantic versioning rules to resolve version ranges
• Considers peer dependencies and optional dependencies
• Builds complete manifest of all packages that would be installed

​

Strategy 2: Manifest File Resolution

npm install  # Uses package-lock.json

• Lockfile Parsing: Dependencies already resolved with exact versions
• Direct Analysis: PMG reads resolved dependency list from lockfiles
• No Version Resolution: Skip dependency resolution since versions are locked
• Efficient Processing: Faster analysis due to pre-resolved state

pip install -r requirements.txt

• Manual Resolution Required: requirements.txt contains only direct dependencies
• Transitive Resolution: PMG must resolve all transitive dependencies
• Version Constraint Handling: Processes version specifiers (>=, ==, ~=, etc.)
• Complete Tree Building: Builds full dependency tree similar to direct installs

​

Technical Implementation Details

• package-lock.json
• pnpm-lock.yaml (pnpm)
• Future: yarn.lock support planned

# requirements.txt example
requests>=2.25.0,<3.0.0
django==4.2.7
# -e git+https://github.com/user/repo.git  # Git URLs skipped
flask[async]  # Extra dependencies resolved

• Approximate Version Resolution: Intelligently resolves version ranges (e.g., ^1.2.0)
• Semver Compatibility: Understands semantic versioning rules
• Peer Dependency Analysis: Considers peer dependency requirements
• Lock File Interpretation: Respects existing lock file constraints

​

3. Threat Detection System

​

Malicious Package Database

• Continuously updated database of known malicious packages
• Real-time scanning of new packages as they’re published
• Community-driven threat intelligence sharing

​

Behavioral Analysis

• Static analysis of package contents
• Detection of suspicious code patterns
• Identification of obfuscated malicious code

​

Name-based Detection

• Typosquatting pattern recognition
• Dependency confusion attack detection
• Suspicious naming convention analysis

​

Supported Ecosystems & Limitations

​

Currently Supported

​

Registry Scope Limitations

• Git URLs (pip install git+https://...)
• Local file paths (pip install ./local-package)
• Private registries (pip install -i private-index)
• Alternative indexes (--extra-index-url)

​

Technical Considerations

​

Version Resolution Accuracy

• Complex dependency resolution algorithms vary between package managers
• Version ranges can resolve differently based on existing dependencies
• Lock file states affect final resolution

• Implements heuristic-based resolution that mirrors package manager behavior
• Prioritizes security over perfect version matching
• Continuously improves resolution accuracy based on real-world usage

​

Performance Characteristics

1. Network Requests: API calls to SafeDep Cloud for threat intelligence
2. Dependency Computation: Local dependency tree analysis
3. Threat Evaluation: Package risk assessment

• Intelligent caching of threat intelligence data
• Parallel dependency analysis where possible
• Minimal network overhead through efficient API design

​

Operating Modes

# Silent mode - minimal output
pmg --silent npm install express

# Verbose mode - detailed analysis information
pmg --verbose npm install express

# Dry run - analyze without installing
pmg --dry-run npm install express

# Debug mode - comprehensive logging
pmg --debug --log /tmp/pmg.log npm install express

​

Integration Patterns

​

Development Environment Integration

# One-time automated setup
pmg setup install

# Manual per-command usage
pmg npm install lodash

​

Security Model

• Known malicious packages: Blocked immediately with detailed warnings
• Suspicious packages: Prompt for user confirmation with a detailed report link for review
• Verified clean packages: Allowed without interference