Cybersecurity is used to protect an infrastructure and its data. But what jobs can you do in this field? In this article, we introduce you to the job of Pentester, the skills of which are taught with our Cyber Fullstack training! We tell you more in this article about the necessary training, the skills and the salary!
Definition of Pentester/Ethical Hacker
Pentester is a contraction of the two words "Penetration" and "Testing" (=Pentesting).
The pentester is a professional who ensures the security of computer networks by means of penetration tests which consist of finding security flaws in a system and carrying out controlled attacks.
These flaws are not just about security breaches that make it possible to remotely control a machine. They also concern the simple disclosure of information by a system that can alert a hacker and lead him to launch an attack or hacking. The pentester enables its client to objectively assess the current level of security of its system and assists it in improving it.
This professional is also called an Ethical Hacker, although there are subtle differences between these two terms. The Ethical Hacker, also called White Hat Hacker, bases his actions on the hacker's ethics: to put forward the freedom of information and the improvement of the qualities of life. The term Ethical Hacking is thus used to designate a set of hacking techniques and attacks which allow the detection of security flaws subject to the owner's consent.

The role and tasks of the Pentester
The main mission of a Pentester is to ensure the computer security of his clients' systems. To this end, he relies on his knowledge of hacking techniques to :
- identify vulnerabilities in the security system,
- assess the risk of attack associated with each identified vulnerability,
- propose adapted solutions in a prioritised manner.
The Pentester, thanks to the intrusion test, is thus able to accurately assess the severity of the breach identified, the complexity of the corrections to be made and their order of priority.
Intrusion testing can be carried out from the outside via a simple internet connection or from within the infrastructure on the company's internal network.
The missions of the Pentester or Ethical Hacker also go far beyond penetration testing. They can also concern other aspects such as complete audits for his client company. These can be of different types:
- Source code audit: to analyse the source code of an application in order to identify possible security flaws,
- architecture audits: consist of checking the robustness of an information system in the face of security threats,
- Configuration audit: provide the Pentester with the configuration of a network device. He then compares them with official reference systems to identify any deviation from compliance.
In the course of his work, the Pentester may have access to sensitive or even confidential information. However, he may not use it under any circumstances. They must strictly adhere to the legislation in force and the rules laid down by the auditors. During his legal introduction into his client's system and networks, the Pentester must document the path of attack that he communicates to his client.
Pentesters usually sign a very specific confidentiality clause . They must also immediately report any security breach to their client and delete all traces of testing to avoid their exploitation for malicious purposes.
The skills and qualities of a Pentester
The Pentester's skills
The Pentester profession requires a very good understanding of hacking techniques, software development and computer systems. A solid knowledge of networking and computer security (coding systems, cryptography, security audits, etc.) is also required.
Similarly, a true Pentester must have real skills in programming and web programming languages such as Java and PHP. And for good reason, penetration tests are most often carried out in an automated manner with software applications. Knowledge of Linux and in particular its security-oriented distributions such as Kali Linux is also recommended.
However, this theoretical basis is not enough: practical knowledge must also be acquired.
It can only be done through experience. Participation in Capture the Flag events is a very rewarding experience. Many Pentesters or Ethical Hackers take part in them. The objective is to identify and exploit the vulnerability of a system to break into it. The flags that are the proof of the intrusion are then recovered. To succeed in this type of competition requires knowledge of many hacking tricks and the ability to reuse them at the right moment.
The qualities
Skills and knowledge of hacking techniques alone are not enough to become a good Pentester or Ethical Hacker. In addition, you need to have qualities such as curiosity, dynamism and reactivity.
Ethical behaviour is also a quality that any Pentester who wants to work in the field of IT security must possess.
Ethics and confidentiality reign supreme in his sector and this is what distinguishes him from hackers. In addition, being available and having a taste for challenge are qualities sought after in a Pentester.
Salary and career development for the Pentester
At the beginning of his or her career, a Pentester's salary is at least 3,000 euros per month, or 36,000 euros per year. Depending on their expertise and experience, the average annual salary can reach 48,000 euros. Pentesters, like other professionals, can also experience a career progression. After a few years of experience, they can become intrusion managers and specialise in a particular system (e.g. pentesting of industrial systems). They are also free to go into business for themselves by setting up an IT security consultancy.

Training to become a Pentester
In order to develop the extensive hacking knowledge and skills needed to carry out this activity, quality training is required.
Our Cybersecurity Essentials course provides this knowledge as it covers a wide range of topics such as system threat monitoring and penetration testing. It allows the Pentester or Ethical Hacker to understand the issues of network architectures, security vulnerability identification and data management.
Becoming a Pentester requires a good level in computer science. To achieve this, it is possible to attend a computer engineering school with a specialisation in cybersecurity. A 5-year degree or a 3-year degree is also sufficient for a career in this exciting profession, which is still in its infancy. Some companies also require security certifications to recruit their pentesters. It is therefore practical to have penetration test certifications such as CEH and OSCP in addition to the training.
A CEH or Certified Ethical Hacker is a qualified computer security professional. A CEH certified Pentester has the tools and hacking techniques most used by hackers to become an ethical hacker. The OSCP or Offensive Security Certified Professional certification focuses, like the CEH, on penetration testing and hacking. Similarly, many Pentesters are true self-taught individuals who have taught themselves computer skills and hacking techniques. Some former hackers have even become Pentesters after finding their way back to the right path.