PEN-Test Guiding Principles

Penetration testing, or "PEN-test," is a simulating real-world cyberattacks to identify vulnerabilities and weakness in an organization's computing and physical environments. The goal is to evaluate security posture, uncover exposures before adversaries exploit them, recommend remediation measures, and validation of mitigating controls or remedy. Penetration tests can adopt various approaches, such as external, internal, or cloud environments, and building or office premises, depending on the engagement scope.

 

Engaging organizational legal counsel is critical to ensure testing aligns with jurisdictional regulations, contractual agreements, and ethical standards, safeguarding the organization from legal or reputational risks.

 

1. Engagement Authorization and Legal Framework 

• Scope and Statement of Work (SOW)
• Documented consent from stakeholders authorizing penetration testing
• Ensuring sign-off, preferably on a need-to-know basis to authorized personnel with decision-making authority and need-to-know basis
• Out of Scope and boundary definitions
• Jurisdictional Compliance
• Adherence to application local, national, and internal laws (e.g., Privacy Act, GDPR and HIPAA)
• Awareness of legal limitations on ethical hacking in specific regions and through public internal network and organizations
• Written consent for any sharing with outside and any third-parties
• Data Protection
• Information protection and discovery criteria or limitations
• Data eradication and secure purging of data collected
• Protocol for unexpected data discovery 

 

2. Timeframe and Frequency

• Frequency:
• At least annually for critical systems
• After major infrastructure changes (e.g., new system deployment, major updates) for best practices
• Following significant compliance requirements (e.g., PCI DSS, ISO 27001, NIST)
• Engagement Duration:
• Scope dependent but typically 2–6 weeks, varying complexity of the environment and number of facets

 

3. Facets of Penetration Testing

Penetration tests may cover a variety of areas, including:

• External Testing: Simulates attacks from external actors targeting publicly accessible systems like web servers, APIs, and other perimeter systems
• Internal Testing: Evaluates risks posed by malicious insiders or compromised internal devices
• Black Box Testing: Simulates an external attacker with no prior knowledge of the systems
• White Box Testing: Conducted with system information/knowledge such as account provisioned, limited source code access, or provided architecture details
• Gray Box Testing: Combines elements of both white and black box testing for targeted assessment.
• Purple Box Testing: Hybrid testing approach that combines elements of both offensive (red team) and defensive (blue team) cybersecurity practices
• Phishing/Social Engineering: Simulates email phishing campaigns and other social engineering tactics to assess user awareness and response to electronic or physical measures
• Physical Testing: Assesses physical security measures, such as access control to buildings, sensitive areas, and equipment
• Wireless Testing: Evaluates the security of Wi-Fi networks, connected devices, and other IoT (Internet of Things)
• Cloud Environment Testing: Focuses on cloud-hosted infrastructure and services, adhering to cloud security processes and industry best practices

 

4. Methodology Best Practices

A well-defined methodology ensures a consistent, repeatable, and thorough approach to penetration testing. Industry-recognized frameworks provide the foundation for best practices:

• Planning and Preparation
• Define scope, objectives, and rules of engagement (ROE)
• Identification of crown-jewels and sensitive information and locations
• Staged access credentials and approvals
• Information Gathering 
• Use open-source intelligence (OSINT) to gather publicly available data
• Perform reconnaissance to map network topology, domains, and services
• Vulnerability Identification
• Identify vulnerabilities using automated scanners and manual testing techniques
• Prioritize vulnerabilities based on potential impact and exploitability
• Responsiveness of operations teams, SOC Security Operations Center) and NOC (Network Operations Center)
• Exploitation
• Attempt to exploit identified vulnerabilities to validate risk
• Use a combination of automated tools and manual techniques to ensure thorough coverage
• Document steps and outcomes without causing harm to production systems
• Screenshots to evidence threat and exposure or exploit
• Measurement of backup and recovery processes and operations, where applicable and allowable
• Post-Exploitation
• Assess the impact of successful exploitation, such as access to sensitive data or privilege escalation
• Risk analysis and quantification based on data or facility impact and likelihood 
• Validate remediation measures post-engagement, if applicable
• Reporting and Remediation Guidance
• Provide actionable recommendations for remediation
• Align findings with frameworks such as CVSS (Common Vulnerability Scoring System), NIST Special Publication 800-115 (Technical Guide to Information Security Testing and Assessment), OWASP Testing Guide (Open Web Application Security Project), and PCI DSS Penetration Testing Guidance
• Risk mapping with organization's risk tolerance and processes

• Engagement Presentation
• Overview of engagement goals, findings, and overall security posture to stakeholders
• Actionable recommendation to ensure alignment of testing outcomes and drive informed decision making

5. Reporting Standards

A comprehensive penetration testing report should include the following sections and encompass details discussion. All reports and communication shall be confidential and encrypted.

• Executive Summary
• Non-technical overview of findings and their potential business impacts
• Description of overall strengthens and weakness observed
• Risk prioritization (e.g., critical, high, medium, low)
• Key recommendations
• Technical/Details Section
• Methodologies used, including tools, tactics, and techniques or procedures
• Detailed findings for each identified vulnerability, with severity ratings
• Proof of Concept (PoC) evidence where applicable (e.g., screenshots, logs)
• Remediation steps for each vulnerability
• Adherence to incident management including IRP (Incident Response Teams)
• References to industry standards (e.g., CVSS scoring, OWASP Top 10)
• Appendices
• Full list of tested systems and environments
• Limitations or exclusions in scope
• Credentials, scripts, or configurations used (if agreed to share)

 

6. Penetration Tester Qualifications

• Expert security firm with reputable industry experience
• Alignment with organizational standards, select a firm through established vendor vetting or a Request for Proposal (RFP) process
• Regular rotation (typically every 2-3 years) enhances the quality and integrity of security assessments, and ensure fresh perspectives or avoids bias
• Certified professionals with relevant credentials, such as:
• OSCP (Offensive Security Certified Professional)
•  OSCE (Offensive Security Certified Expert)

• GPEN (GIAC Penetration Tester)
• CEH (Certified Ethical Hacker)
• CREST-certified tester (for specific compliance requirements)
• Demonstrable experience in testing environments similar to the client's scope
• Familiarity with compliance and regulatory frameworks (e.g., GDPR, PCI DSS, NIST)
• Commitment to ethical hacking principles and a signed NDA (Non-Disclosure Agreement)

 

By simulating real-world attack scenarios, pen-testing provides actionable insights to strengthen computing environments, comply with regulatory requirements, and safeguard critical assets against evolving cyber threats. Ultimately, the goal should be to establish continuous penetration testing as an ongoing security practice, enabling organizations to proactively detect and address vulnerabilities and threats in real-time and elevate adaptive security model.