CyberSecurity & DevSecOps Expert: Develop, PenTest, and Deploy Secure Applications

Why every action must be written down You now have an isolated lab, a training target and snapshots that let you go back after a mistake. The next professional habit is just as important as the lab itself: recording what you do, as you do it. In cybe...

Why you need a legal training target You now have a working lab. You have virtualisation software, a security-focused Linux virtual machine, snapshots to undo your mistakes, and network isolation that keeps your lab apart from your home network. One ...

Why isolation is the rule of the game You now have virtualisation software, a security-focused Linux virtual machine and snapshots to undo your mistakes. One question remains: what can this machine reach? By default, a new virtual machine (VM) is usu...

What a snapshot is and why you need one You have created your first Linux virtual machine (VM) in your virtualisation software. You will soon break it, and that is normal. You will install the wrong package, misconfigure the network, delete a system ...

What a security-focused Linux distribution is You now have virtualisation software installed on your computer. The next step is to choose the operating system (OS) that will run inside your first virtual machine (VM). In cybersecurity, that OS is alm...

What virtualisation is and why your lab depends on it In the previous activity, you saw why an ethical hacker always trains in a lab and never on a real system. You now need the technology that makes this lab possible on a single laptop: virtualisati...

The lab answers the authorisation problem In the previous activities, you learned one central rule. The only difference between a penetration test and an attack is written authorisation from the owner of the system, within a defined scope. This rule ...

Four families, one shared incident In your previous activities, you followed an incident from start to finish: someone attacks, someone detects and responds, someone investigates, and the organisation then fixes its weaknesses. Each of these moments ...

From authorisation to scope In the previous activities, you learned that the only difference between an ethical hacker and an attacker is authorisation. Authorisation alone is not enough, though. An authorisation always applies to something precise: ...

Why the law is your first tool In the previous activity, you saw that the only thing separating an ethical hacker from a criminal is authorisation. This lesson explains what that means in law. The commands, tools and techniques used by a penetration ...

Same techniques, opposite status In the previous activities you studied attackers, their motivations, attack families and how an incident unfolds from intrusion to investigation. Here is the key idea of this lesson. An ethical hacker uses exactly the...

Why follow an incident from start to finish You already have the basic vocabulary of cybersecurity. You can tell a threat from a vulnerability and a risk. You know who attacks and why, and which property of confidentiality, integrity and availability...

Phishing: attacking the human You now know how to name a threat, a vulnerability and a risk. You know who attacks and why, and which property is hit: confidentiality, integrity or availability (the CIA triad). This lesson adds the missing piece, whic...

Why security needs a clear target In the previous activities you learned to separate a threat, a vulnerability and a risk, and you met the attackers who exploit them. One question remains: what exactly is damaged when an attack succeeds? Cybersecurit...

Core Concepts Recap You have recently learned the crucial difference between threat, vulnerability, and risk. A threat is a potential cause of an unwanted incident, like a hacker. A vulnerability is a weakness in a system, such as outdated software. ...

Why you must know your attacker In the previous lesson, you learned to separate three words: a threat is what can cause harm, a vulnerability is the weakness that harm exploits, and a risk combines the likelihood of an attack with its impact. This le...

Why these three words matter In the welcome activity, you saw that cybersecurity protects information and the systems that carry it. To do that job, professionals use a precise vocabulary. Three words come up in every meeting, audit report and penetr...

Welcome to the Ethical Hacker and Cyber Defence course. You are starting from scratch, and that is fine. By the end of this path you will understand how systems and networks work, how attackers think, how defenders respond, and how to carry out a com...

## Context You are hired as a junior security analyst for a startup that publishes a public REST **Weather API**. This API exposes endpoints such as `GET /weather?city=`, `GET /forecast?lat=&lon=`, `POST /users` (registration), `POST /login` (authent...

Threat modeling is only useful if the results are captured, shared, and kept up to date. A threat model that lives in someone's head or in an outdated diagram provides no value to the team. This chapter explains how to document a threat model properl...

THEORETICAL RECAP Threat modeling is the structured practice of identifying, communicating, and understanding threats and mitigations within the context of protecting an application. OWASP Threat Dragon is a free, open-source tool that lets you draw ...

Threat modeling is only as effective as the tools you use to draw, document, and share it. Up to now, you have learned the concepts: confidentiality, integrity and availability (the CIA triad), the STRIDE categories, attack surface analysis, security...

THEORETICAL RECAP A security test checklist derived from a threat model is not a fixed artifact: it must be adapted to the specific context of the target. A third-party public API differs sharply from an internal service. Key definitions: a 'third-pa...

This case study connects everything you have already studied: the STRIDE threat categories, the attack surface, the security principles, the OWASP Risk Rating methodology, the correction and testing heuristics, and the security checklist. The goal he...

THEORETICAL RECAP A threat model is a structured description of what can go wrong in an application: assets to protect, entry points (attack surface), threats (typically classified via STRIDE: Spoofing, Tampering, Repudiation, Information disclosure,...