Offensive Security

Penetration Testing Methodology: A Comprehensive Guide

Master the systematic approach to ethical hacking and security assessment through proven penetration testing methodologies.

January 12, 2025 15 min read

What is Penetration Testing?

Penetration testing, often called "ethical hacking," is a systematic process of evaluating information system security by simulating attacks from malicious actors. It involves authorized attempts to exploit vulnerabilities in applications, systems, and networks to assess the organization's security posture.

Types of Penetration Testing

Black Box Testing

No prior knowledge of the target system. Simulates external attacker perspective.

White Box Testing

Full knowledge of system architecture, source code, and documentation.

Gray Box Testing

Partial knowledge combining internal and external testing approaches.

The PTES Methodology

1

Pre-engagement Interactions

Define scope, establish rules of engagement, and obtain proper authorization.

  • • Scope definition and target identification
  • • Rules of engagement documentation
  • • Statement of Work (SOW) creation
  • • Legal agreements and authorization
  • • Contact information and escalation procedures
2

Intelligence Gathering

Collect information about the target organization and infrastructure.

OSINT Sources:

  • • Company websites and social media
  • • DNS records and WHOIS data
  • • Job postings and employee profiles
  • • Public documents and filings
  • • Search engine reconnaissance

Technical Reconnaissance:

  • • Network range identification
  • • Email harvesting
  • • Technology stack analysis
  • • Third-party relationships
  • • Physical location intelligence
3

Threat Modeling

Analyze potential attack vectors and prioritize threats based on business impact.

  • • Asset identification and classification
  • • Threat actor profiling
  • • Attack vector analysis
  • • Risk assessment and prioritization
  • • Business impact evaluation

Active Testing Phases

4

Vulnerability Analysis

Identify and validate security vulnerabilities in the target environment.

Common Tools:

• Nmap
• Nessus
• OpenVAS
• Burp Suite
• Nikto
• SQLmap
• Dirb/Gobuster
• Nuclei
  • • Network service enumeration
  • • Web application vulnerability scanning
  • • Configuration weakness identification
  • • Manual vulnerability verification
  • • False positive elimination
5

Exploitation

Attempt to exploit identified vulnerabilities to gain unauthorized access.

Exploitation Techniques:

  • • Buffer overflow exploitation
  • • SQL injection attacks
  • • Cross-site scripting (XSS)
  • • Privilege escalation
  • • Social engineering

Exploitation Frameworks:

  • • Metasploit Framework
  • • Cobalt Strike
  • • Empire/Starkiller
  • • Custom exploit development
  • • Social engineering toolkit
6

Post-Exploitation

Determine the impact of successful exploitation and gather evidence.

  • • Privilege escalation attempts
  • • Lateral movement exploration
  • • Data access demonstration
  • • Persistence mechanism installation
  • • Network pivoting and tunneling
  • • Evidence collection and documentation

Essential Penetration Testing Tools

Network Testing

  • Nmap: Network discovery and port scanning
  • Masscan: High-speed port scanner
  • Wireshark: Network protocol analyzer
  • Netcat: Network utility for connections
  • Hping3: Network tool for packet crafting

Web Application Testing

  • Burp Suite: Web application security testing
  • OWASP ZAP: Web application scanner
  • SQLmap: SQL injection testing tool
  • Nikto: Web server scanner
  • Gobuster: Directory/file brute-forcer

Exploitation & Post-Exploitation

  • Metasploit: Exploitation framework
  • Mimikatz: Credential extraction
  • BloodHound: Active Directory mapping
  • PowerShell Empire: Post-exploitation agent
  • Cobalt Strike: Advanced threat emulation

Reporting and Documentation

Executive Summary

  • • High-level findings and business risk
  • • Overall security posture assessment
  • • Strategic recommendations
  • • Compliance gap analysis

Technical Findings

  • • Detailed vulnerability descriptions
  • • Proof-of-concept demonstrations
  • • Risk ratings and CVSS scores
  • • Remediation recommendations
  • • Evidence and screenshots

Legal and Ethical Considerations

⚠️ Critical Legal Requirements

  • Written Authorization: Always obtain explicit written permission
  • Scope Limitations: Stay within defined testing boundaries
  • Data Protection: Handle sensitive information responsibly
  • System Stability: Avoid causing system outages or data loss
  • Disclosure Responsibility: Report findings promptly and securely
  • Tool Restrictions: Use only approved testing tools and techniques

Industry Standards and Frameworks

Testing Standards

  • • PTES (Penetration Testing Execution Standard)
  • • OWASP Testing Guide
  • • NIST SP 800-115
  • • OSSTMM (Open Source Security Testing)
  • • ISSAF (Information Systems Security Assessment)

Certifications

  • • OSCP (Offensive Security Certified Professional)
  • • CEH (Certified Ethical Hacker)
  • • GPEN (GIAC Penetration Tester)
  • • CPTE (Certified Penetration Testing Engineer)
  • • OSWE (Offensive Security Web Expert)

🎯 Key Success Factors

Effective penetration testing requires a systematic methodology, proper authorization, skilled execution, and clear communication. The goal is not just to find vulnerabilities, but to help organizations understand their security risks and improve their overall security posture through actionable recommendations.