Penetration testing, commonly referred to as "pentesting", is one of my favorite activities and a reason why I thoroughly enjoy my job in cybersecurity! I decided to write a series of blogs about my specific external pentesting approach to help any readers who are interested in pursuing a pentesting career path. Bear in mind, the methodologies and approaches I describe are based on my own preferences - other pentesters and professionals have different ways of doing things.

Also, as I write these blogs, I assume that readers have some fundamental understanding of pentesting and cyber/information security. I won't go in-depth over things like black box vs gray box testing, the different kinds of testing services, etc.

I find it's best to communicate my pentesting process by applying it to a scenario. Throughout this Pentesting blog series, we'll assume that we work for a company called Turbo Tactical, which specializes in offering a variety of security services including pentesting services. Our customer is Techno Global Research Industries (or, TGRI).

What is an External Penetration Test?

A pentest is a proactive security assessment aimed at identifying vulnerabilities and weaknesses in an organization's external-facing systems. This form of ethical hacking simulates real-world cyberattacks, providing insights into potential entry points for malicious actors. It typically focuses on external assets such as web applications, networks, and servers that are accessible from the internet. A pentest might be done to ensure compliance with regulations or to uphold the integrity of sensitive data like proprietary or Personally Identifiable Information (PII).

Approach to External Pentesting

Every pentester brings a unique perspective and approach to their work. In this blog series, I'll share the methodologies I use, influenced by insights gained from resources like TCM Academy, CompTIA, SANS, and the broader cybersecurity community. While I don't claim to originate these approaches, they reflect a collective understanding of effective penetration testing techniques.

Pentest Roadmap

Without careful attention, pentesting may become a chaotic process, leading to the omission of crucial steps. The last thing you want is to discover overlooked or inaccurately reported findings during client reviews. Such errors can harm your professional reputation and credibility with clients or employers.

Here are the basic phases that I follow throughout a pentesting engagement:

graph TD; A[Planning] B[Passive Reconnaissance] C[Active Reconnaissance] D[Vulnerability Identification] E[Manual Validation] F[Threat Modeling] G[Exploitation] H[Post-Exploitation] I[Reporting] A -->|Define scope, goals, and rules of engagement| B B -->|Gather public information, WHOIS, DNS| C C -->|Network scanning, Port scanning| D D -->|Use tools to identify vulnerabilities| E E -->|Manually verify vulnerabilities| F F -->|Assess potential threats and risks| G G -->|Attempt to exploit vulnerabilities| H H -->|Review, document, and secure the environment| I

Methodology vs Tools

While methodologies provide structured frameworks, a tool-based approach relies heavily on automated tools. A balanced approach is often ideal. Methodologies guide the overall process, ensuring comprehensive coverage, while tools automate repetitive tasks, allowing testers to focus on critical thinking and manual validation. A methodology-based approach promotes a deeper understanding of security concepts, while a tool-based approach can expedite certain phases. A successful pentester integrates both approaches for a robust and efficient engagement.

Conclusion

In conclusion, external penetration testing serves as a critical component in ensuring the security robustness of an organization's digital infrastructure. By systematically navigating through the carefully planned roadmap, we can uncover vulnerabilities and potential threats that could otherwise remain hidden. Every pentester brings a unique approach and methodology to the table, often shaped by the rich tapestry of resources available from industry leaders and experienced peers.

As we delve into the intricacies of this dynamic field, it's imperative to strike a balance between methodology-based strategies and the judicious use of cutting-edge tools. While methodologies provide a structured framework for assessment, tools enhance efficiency and expand the depth of our analyses. The careful orchestration of both approaches is the key to a successful external penetration test.

In the next blog, I will cover the steps that I use when planning a pentesting engagement.