Pentesting Fundamentals Writeup

Date: 04-02-2026 | Platform: TryHackMe | Difficulty: Easy | PT1 Exam Preparation

Overview

This room covers the foundational concepts of penetration testing, including methodologies, ethics, and practical application. Essential knowledge for anyone pursuing the PT1 certification and understanding the penetration testing lifecycle.

Task 1: What is Penetration Testing?

A penetration test is an ethically-driven attempt to test and analyse the security defences to protect assets and information. It involves using the same tools, techniques, and methodologies that someone with malicious intent would use.

Key Statistics: According to Security Magazine, there are over 2,200 cyber attacks every day - 1 attack every 39 seconds.

Task 2: Penetration Testing Ethics

The battle of legality and ethics in cybersecurity is controversial. Labels like "hacking" and "hacker" often hold negative connotations, making the idea of legally gaining access to computer systems challenging to grasp.

Legal vs Ethical:

A penetration test is an authorised audit of a computer system's security and defences as agreed by the owners. Anything outside this agreement is deemed unauthorised.

Hat Categories:

Rules of Engagement (ROE):

Document created at initial stages defining how penetration testing engagement is carried out:

Key Points:

  • NCSC has CHECK accreditation scheme in UK for authorised penetration tests
  • Penetration testers face morally questionable decisions (e.g., accessing sensitive data)
  • Actions may be legal but ethically questionable

Task 3: Penetration Testing Methodologies

Penetration tests can have a wide variety of objectives and targets within scope. No penetration test is the same, and there are no one-case fits all approaches.

General Testing Stages:

OSSTMM (Open Source Security Testing Methodology Manual):

OWASP (Open Web Application Security Project):

NIST Cybersecurity Framework 1.1:

NCSC CAF (Cyber Assessment Framework):

Task 4: Black Box, White Box, Grey Box Penetration Testing

Black-Box Testing:

High-level testing process where the tester is not given any information about the inner workings of the application or service.

Grey-Box Testing:

Most popular for penetration testing - combination of black-box and white-box testing.

White-Box Testing:

Low-level process usually done by software developers with programming knowledge.

Task 5: Practical: ACME Penetration Test

ACME has approached you for an assignment. They want you to carry out the stages of a penetration test on their infrastructure.

Practical Exercise Overview:

View the site and follow the guided instructions to complete this exercise.

Exercise Completion:

Flag: THM{PENTEST_COMPLETE}

Key Learning Points:

PT1 Exam Relevance

This room covers fundamental concepts essential for the PT1 certification:

Key Takeaways