Testing for better defense
A computer system, no matter how modern, is never free of flaws. Some are visible, others much more discreet. Penetration testing, or PenTest, consists in simulating a real attack to identify vulnerabilities before an attacker does.
It's an essential practice for any company wishing to strengthen its cybersecurity in order to prevent potentially costly or reputation-damaging incidents.
What is a PenTest?
A PenTest is a controlled attack simulation carried out by cybersecurity experts. These professionals put themselves in the shoes of hackers to test the robustness of your information system. Their objective: to find exploitable flaws in your infrastructures, applications, configurations or processes.
Unlike real attacks, everything is carried out in a secure environment and with your agreement. The sole aim is to reinforce your protection.
Why is it essential?
An untested system is an easy target. A PenTest enables you to :
- Detect vulnerabilities before they are exploited;
- Assess the robustness of your technical and organizational defenses;
- Meet regulatory obligations, such as those imposed by DORA for companies in the financial sector;
- Prepare your company for real-life threats.
When is the best time to carry out a PenTest?
When is the best time to carry out a PenTest? Before an attacker does it for you.
More concretely, we recommend that you carry out a PenTest :
- After a major production launch;
- When deploying a new application or web service;
- After migration to the cloud;
- If you have any doubts about the security of a critical perimeter.
How does PenTest work?
A PenTest generally follows several stages:
- Definition of the perimeter and rules with the company (what is tested, when, with what constraints).
- Exploration phase to gather as much information as possible about the target.
- Simulation of attacks to try to exploit the vulnerabilities discovered.
- Analysis of results.
- Delivery of a detailed report, with concrete recommendations and vulnerability criticality levels.
Everything is carried out within an ethical, secure and confidential framework.
The different PenTest approaches
There are three main methods, depending on the level of information provided to testers:
- Black box: the attacker has no prior information (like an external hacker).
- White box: testers have full access (source code, user accounts, documentation).
- Grey box: testers have limited access, simulating an attacker who has already broken through an initial security barrier.
Each approach has its advantages, and allows you to test complementary aspects of the system.
What happens after the test?
At the end of the PenTest, a full report is issued. It contains :
- A list of the vulnerabilities discovered;
- Their criticality level (minor to critical);
- Concrete recommendations adapted to your environment;
- In some cases, remediation support.
The aim is not just to point out vulnerabilities, but to improve your security posture in the long term.
Who is concerned by PenTests?
All companies are concerned, but some are particular targets:
- The financial sector;
- e-commerce
- Healthcare organizations;
- Industries handling sensitive or critical data.
If you handle confidential data, are subject to strict regulations or want to validate the effectiveness of your defenses, a PenTest is no longer an option - it's a strategic necessity.
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This article is based on an interview with Michael Weydert in Dattak Décode. Watch the full episode on our YouTube channel. Cyber risk is the number 1 risk for any company, whatever its size.