Penetration testing or pentesting for cyberattack prevention

Proactive cybersecurity is becoming an essential security measure with the current increase and growing sophistication of cyberattacks. It consists of various actions and security measures that help companies protect themselves. One of these measures is penetration testing, also known as pentesting.

What is pentesting?

A penetration test is a type of security audit in which a team of cybersecurity professionals, called pentesters or ethical hackers, simulate real attacks against a company’s computer systems, networks, or applications in order to identify vulnerabilities, configuration weaknesses, or failures in security controls.

The goal is not to compromise the infrastructure to damage it, but to detect its flaws in a controlled way before cybercriminals discover and exploit them to launch their threats. This allows the organization to implement the appropriate security measures to mitigate these risks.

Types of pentesting

Depending on the pentester’s level of prior knowledge about the system, different approaches can be used.

Black-box

The auditor has no internal information about the system and acts like an external attacker without credentials, relying only on publicly accessible data (for example, domain, IP, URLs…). This approach simulates real attacks from the outside.

White-box

The auditor has internal information, architecture, source code, credentials, network design, which allows for a thorough examination of potential internal vulnerabilities, misconfigurations, poor coding practices, and more.

Grey-box

An intermediate approach, where the auditor has partial information about the system, such as user credentials or partial diagrams. This makes it possible to simulate attacks from a malicious legitimate user or an attacker with limited access.

Pentest methodology and phases

Although there are multiple frameworks and standards, such as PTES (Penetration Testing Execution Standard), OSSTMM (Open Source Security Testing Methodology Manual), or internal and regulated audit guidelines, the core phases that typically make up a pentest are fairly consistent.

Broadly speaking, the typical process is as follows: 

1. Reconnaissance / Information Gathering: Collecting as much information as possible about the target: domains, IP addresses, subdomains, technologies in use, software versions, public configurations, exposed users, etc. This step is crucial for defining the scope of the pentest.
   
   
2. Vulnerability Analysis and Scanning: Using both automated and manual tools to detect potential vulnerabilities, open ports, exposed services, vulnerable versions, weak configurations, coding errors, and more.
   
   
3. Exploitation: Attempting to leverage those vulnerabilities to compromise the system, gaining access, escalating privileges, executing code, etc., always within the agreed scope.
   
   
4. Post-Exploitation / Pivoting: If permitted by the pentest rules, the tester may move laterally from the initial compromised point to access other internal systems, escalate privileges, or compromise sensitive data, simulating real attack scenarios.
   
   
5. Reporting: The final phase consists of documenting all discovered vulnerabilities, evidence, associated risks, potential impacts, and most importantly, concrete recommendations for mitigating them. This report must be clear and useful for both technical teams and management.

Benefits of conducting pentesting for a company

Regularly implementing penetration tests as part of a company’s cybersecurity strategy, alongside proactive security solutions, is essential to ensuring its protection.

• Early identification of real vulnerabilities: The main goal of pentesting is to detect vulnerabilities before they can be exploited by cybercriminals. This allows companies to proactively fix them through software updates, configuration hardening, strengthening controls, or architectural adjustments, significantly reducing the risk of incidents.
  
  
• Improves overall security posture: By uncovering weaknesses or security gaps, companies can strengthen their defenses, add protection layers, harden access policies, isolate critical areas, and generally increase their resilience to attacks.  
  
  
• Detection of complex issues and business logic flaws:
  Many vulnerabilities, such as business logic errors, insecure workflows, poor access control, or authentication/authorization flaws, cannot be identified through automated scans. Only manual pentesting conducted by professionals can reveal these deeper issues.
  
  
• Regulatory and compliance requirements: For many companies, performing regular security audits, including pentesting, is required by data protection laws, security standards, or industry-specific regulations (for example, for businesses handling payments, personal data, remote access, etc.). Conducting a pentest helps demonstrate due diligence and compliance with privacy regulations, audits, and security standards.
  
  
• Incident preparedness: A pentest not only identifies technical vulnerabilities but also assesses the effectiveness of the company’s detection, response, and monitoring controls. This helps improve incident response plans, reduce detection time, minimize damage, and restore operations more quickly. 
  
• Cost savings and financial risk reduction: The average cost of a security breach can be extremely high, especially if it involves the loss of sensitive data, regulatory issues, fines, or reputational damage. Investing in pentesting and vulnerability remediation significantly reduces this risk, helping prevent incident-related expenses.  
  
  
• Internal Awareness and Cybersecurity Culture: The report generated after a pentest helps both the IT team and management understand real risks, prioritize security investments, allocate proper resources, and promote a security-focused corporate culture.

Limitations and considerations for using pentesting appropriately

It is important to understand that a pentest has a limited and finite scope. Only the systems, applications, or environments included within the defined scope will be evaluated. Therefore, clearly defining the scope (network, internal infrastructure, applications, APIs, remote access, etc.) is critical.

On the other hand, a pentest does not guarantee that all vulnerabilities will be detected. Some attack vectors or highly specific logic flaws may escape the audit, especially if only automated scans are used or if real-world usage scenarios are not simulated.

A pentest reflects the security status at the time of the audit. Over time, changes such as new features, patches, updates, configuration adjustments, personnel changes, or new systems may introduce new vulnerabilities. For this reason, it is recommended to conduct tests periodically.

Finally, there is a risk of service disruption (depending on the type of pentest), particularly when performed on production environments. Therefore, it is important to coordinate timing, maintenance windows, and, in some cases, use test environments or sandboxes.

Penetration testing has become a key strategic action for protecting systems and information, as well as ensuring business continuity.

By detecting vulnerabilities before cybercriminals do, improving the security posture, complying with regulations, preparing more effective incident response plans, and fostering a corporate cybersecurity culture, pentesting provides a high return compared to the potential cost of a breach.