What is Pentesting in Cybersecurity?

Do you know what pentesting is and why it could save your company from a major headache? Pentesting (or penetration testing, if we want to be more formal) is basically a way to stay ahead of cyberattacks. How? By simulating real attacks in a controlled environment to detect security flaws before real hackers find them. It's like hiring someone to try to break into your system... only with your permission and with the goal of making it more secure.

Thanks to these tests, companies can find weak points in their systems, reinforce them in time, and thus avoid data breaches, financial losses, and other problems no one wants to deal with.

In this article, we're going to tell you everything you need to know about pentesting: what it is exactly, the types that exist, when it's a good idea to run these tests, and more.

What is Pentesting and What Is It For?

Pentesting, also known as a pentest, is a technique used to identify vulnerabilities in a company’s systems. As we mentioned before, it’s about simulating an attack (yes, like a hacker would) but with the intent of finding flaws and fixing them before someone with bad intentions does.

In fact, the term comes from the English words penetration and test. Basically: seeing if it’s possible to “get in” where one shouldn’t.

And why is it important? Because it helps detect gaps in web applications, databases, networks, and other critical systems. It's an effective way to protect sensitive information and prevent unauthorized access.

Now that you know what pentesting is, you're probably wondering: “So who performs these tests?” Well, that person is the pentester.

What Is a Pentester and What Do They Do?

A pentester (or ethical hacker, as they’re also known) is a cybersecurity expert who tests a company’s systems... but from the good side. Their job is to simulate real attacks (in a controlled way and with permission) to discover security flaws before a real hacker does. In other words, they try to “break” systems, but with the goal of making them stronger.

Here are some of their main tasks:

1. Launching controlled attacks on systems to find vulnerabilities.

2. Using specialized tools to scan networks, search for known bugs, or exploit security flaws.

3. Reviewing application code to find weak points.

4. Testing the team with social engineering techniques (like phishing emails or fake calls) to see if they might fall for a trap.

5. Documenting everything they find and providing recommendations to fix the issues.

6. Working alongside the technical team to implement the necessary improvements.

What Is Pentesting Used For?

In addition to detecting vulnerabilities, pentesting also helps verify that a company complies with certain security standards, such as ISO 27001 or SOC 2. It also serves to measure how prepared the organization is for a potential attack and how aware employees are about information security.

When this kind of assessment is performed, everything that’s found is reported to the system administrators, who are responsible for fixing those gaps before someone else can exploit them.

And once the corrections have been made, a retest is carried out — that is, the tests are repeated to confirm that everything has been properly resolved. (Later on, we’ll explain all the phases of a penetration test in detail.)

How Often Should Pentesting Be Done?

Ideally, at least two tests should be done per year, especially on the company’s most important or critical systems. It’s also recommended to run a test whenever there are major changes to the infrastructure, such as code updates, migrations, or new integrations.

This way, companies can ensure that no new vulnerabilities have been introduced that attackers could exploit to gain unauthorized access.

Read more: What is Recon-NG?: A Reconnaissance Tool for Ethical Hacking

Why Is It Important for Companies to Do Pentesting?

Penetration testing isn’t a luxury — it’s a necessity. Pentesting helps you find vulnerabilities before attackers do, giving you time to act and protect your data. Here are some strong reasons why every company should perform pentesting:

1. Avoid Major Financial Losses: A cyberattack can bring down your services, steal your data, or even land you in legal trouble. Detecting flaws in time can save you a lot of money (and headaches).

2. Protect Your Reputation: A data breach can ruin your company’s image in seconds. By showing that you take security seriously, your clients and partners are more likely to trust you.

3. Meet Compliance and Regulatory Standards: Many industries require a certain level of security. Pentesting helps you align with standards like ISO 27001, PCI DSS, or SOC 2 and avoid penalties.

4. Stay Ahead of New Threats: Technology is constantly evolving, and so are cyberattacks. Regular pentesting allows you to stay one step ahead and keep your defenses up to date.

Beyond just preventing attacks, a pentest gives you a clear picture of what you’re doing right and where you need to improve in terms of cybersecurity.

Benefits of Pentesting

More than just identifying errors, professional pentesting helps you build a much stronger cybersecurity strategy. These are some of the most important benefits:

1. You Detect and Fix Vulnerabilities Before They Become a Problem

A solid penetration test can identify technical or configuration flaws that could be exploited by an attacker. Best of all: you can fix them in time and then perform a retest to confirm everything is securely closed.

2. You Meet Standards and Pass Audits with Ease

If your company needs to comply with standards like ISO 27001, PCI DSS, SOC 2, or others, pentesting is a key tool. The reports generated can serve as evidence for clients, auditors, and regulators that you’re handling security the right way.

3. You Raise Awareness Across Your Entire Team

The results aren’t just for the IT department. Executive reports are also provided so leadership can understand real risks and make decisions based on data — not assumptions. This helps foster a security-first culture throughout the organization.

4. You Reduce Financial and Other Risks

Types of Pentesting: Which One Is Right for Your Company?

Not all penetration tests are the same. Depending on the level of access given to the pentester, there are three main types:

Black Box Pentesting

In this type of black box test, the pentester has no prior information about the system. They’re only given an IP address or the application's URL, and from there, they try to find vulnerabilities as if they were an external attacker. This helps assess how exposed your systems are from the outside.

Grey Box Pentesting

In a grey box test, the pentester is given some internal information, such as credentials or a general understanding of how the application is built. This allows for more targeted testing and the identification of more critical flaws. It simulates the scenario of someone with partial access, like an employee or registered user.

White Box Pentesting

White box testing is the most complete and detailed. The pentester has full access: credentials, system architecture, and even source code. This allows for a thorough review and the discovery of vulnerabilities that could be missed in other types of tests. However, due to its complexity, it takes the most time.

What Are the Phases of a Pentest?

Pentesting isn’t just about “seeing if someone can get in” to a system. It’s actually a well-structured process with different phases that specialists follow step by step to ensure the test is effective and safe.

Here’s a simple breakdown of each phase and why it’s important for protecting your company’s information:

1. Reconnaissance

First things first: gather information. In this phase, the pentesting team aims to learn as much as possible about the system they’re about to analyze. Don’t worry — they’re not attacking anything yet.

They look for things like IP addresses, visible configurations, publicly available employee data (names, emails, job titles), and even details about the software or infrastructure being used. All this info helps them plan how and where they might try to “sneak in.”

2. Scanning

With the information collected, the next step is to analyze it and check for open doors. In other words, they review whether the detected services have known vulnerabilities.

The goal here is to understand how exposed the system is and how difficult (or easy) it would be to gain access. This phase is crucial for identifying the most obvious weak points that could be used in the next stage.

3. Exploitation

This is the most intense part of the process. With vulnerable points identified, the pentesters now try to break into the system just like a real attacker would.

They test different ways to gain access through those weaknesses, and if successful, continue moving through the system to see how far they can get: Can they view sensitive data? Take full control? Gain admin privileges?

The goal isn’t to cause damage, of course, but to understand how much harm a cybercriminal could potentially do — so those gaps can be closed afterward.

4. Cleanup

After all that activity inside the system, it’s very important to remove any traces of the test. Why? Because any leftover trail could be used by a real attacker later on.

This phase involves ensuring that no “marked paths,” temporary files, open accesses, or testing tools are left behind. Forgetting something could introduce a new risk.

Why Perform Pentesting Regularly?

Every time you run a test like this, you ensure that your system is up to date, free of known vulnerabilities, and that your team is aware of real-world risks. It’s an effective way to stay one step ahead of cyber attackers and continuously strengthen your security.

At TecnetOne, we make cybersecurity and regulatory compliance much simpler for businesses. Our team of certified ethical hackers goes far beyond typical penetration testing.

Discover how our pentesting service can become a key pillar in protecting your business and reinforcing your security strategy.