The importance of penetration testing: strengthening cybersecurity defenses
The unprecedented digital growth humanity has witnessed over the past decade is unparalleled. According to a recent report by Statista on Global Data Usage, the total volume of human-generated data is projected to reach 394 zetabytes by 2028. However, this rapid digitization also creates opportunities for cybercriminals to exploit systems, potentially accessing customers’ personal information, proprietary intellectual property, financial records, and other confidential data for their personal gain.
Thus, it becomes crucial for businesses to continuously reinforce their defenses to protect critical assets. One of the most effective strategies to safeguard your organization is through penetration testing.
This comprehensive guide will break down, “what is penetration testing” why it matters, the methodologies involved, best practices, and the costs associated with it.
What is penetration testing?
A penetration test (or pentest) is an imitation of a cyberattack against a system in order to identify weaknesses that threat actors could use to their advantage. Simply put, penetration testing – often referred to as ethical hacking—is a simulated cyber attack against your computer system, network, or web application to evaluate its security. Moreover, the test is structured around clearly defined phases of a penetration test that are designed to cover all possible entry points and attack vectors.
This process not only tests the system’s ability to withstand an attack but also provides valuable insights into what is the primary goal of penetration testing: to protect sensitive data, ensure business continuity, and maintain customer trust. As per the recent report published by Group-IB on High-Tech Crime Trends 2025, with the increasing adoption of AI, cyber criminals are also expected to use AI to exploit the current IT infrastructure. Thus, it becomes important for organizations to incorporate a “security by design” approach while building solutions for internal and external uses.
Penetration testers use the same methods as threat actors. However, during a pentest, searching for vulnerabilities and developing an attack chain are strictly limited by the boundaries set by the customer and do not affect a given organization’s infrastructure. After a penetration test, the customer receives a report that details how the testing was conducted and provides recommendations on eliminating the vulnerabilities found.
Penetration testing vs. Red teaming
A penetration test does not involve assessing how ready an organization is to detect and respond to security incidents. The focus is on searching for vulnerabilities and exploiting them.
If a company needs to assess how ready its information security department is to handle potential attacks, red teaming is recommended. Red teaming imitates real-life targeted attacks against an entire organization.
Red teaming assesses not only how well the information security system performs but also the staff’s ability to identify and respond to incidents. This specific type of penetration testing is particularly suitable for companies that have their own incident response team.
Who conducts penetration tests?
For a penetration test to be objective, it should be conducted by an external expert who is not familiar with the organization’s information security system. Such specialists usually work at cybersecurity companies and are also called “pen-testers,” “ethical hackers,” and “white-hat hackers.”
A pen-tester is a cybersecurity expert who specializes in searching for vulnerabilities in information systems, assessing potential damage if threat actors were to use those weaknesses, and providing actionable recommendations on how to eliminate detected vulnerabilities. Group-IB has demonstrated successful penetration testing for Libertex Group and Oris Lab to identify the vulnerabilities present in their current IT infrastructure and helped them improve the same.
Why is Penetration Testing essential for your business?
Cybersecurity companies often use threat intelligence solutions to conduct penetration testing. The goal of a penetration test is to detect vulnerabilities in an organization’s information security system. Finding and analyzing weak spots in the infrastructure helps achieve the following objectives:
1. Prevent cyberattacks
Penetration tests help identify weaknesses in information security systems. By eliminating flaws, an organization can strengthen its security posture, thereby making its information systems more complex and less appealing to threat actors.
2. Identify the attack surface
Reconnaissance conducted by a pentester at the start of the test helps look at the company’s systems from a real attacker’s perspective and uncover forgotten or unused IT assets that could be targeted.
3. Continuously improve security
Training relating to previous errors helps developers and administrators of information systems improve their approaches to cybersecurity. Regular penetration tests foster a culture of information security and reduce the number of new vulnerabilities.
4. Regulatory and Compliance Advantages
Many industries are subject to strict regulatory requirements. Regular penetration testing helps ensure that your organization remains compliant with standards such as PCI-DSS, HIPAA, GDPR, and others. Understanding what is penetration testing and its implications on compliance can help mitigate legal risks and potential fines.
5. Financial Benefits and Cost Savings
Although one might wonder how much does penetration testing cost, it’s important to view the expense as an investment rather than a cost. The price of a data breach—both financially and in terms of reputation—can far exceed the expense of a thorough penetration test. Furthermore, by identifying vulnerabilities early, businesses can avoid costly remediation efforts and downtime that might result from a successful cyber attack.
Types of penetration tests
Penetration testing is a versatile security measure that can be tailored to suit various needs. Here, we explore the most common types, providing clear insight into what penetration testing is and its diverse applications.
External penetration testing
This type of test simulates the actions of threat actors who do not have access to the company’s internal network. The pentester’s goal is to detect and use vulnerabilities that make it possible to penetrate the organization’s infrastructure from the outside.
Internal penetration testing
This kind of penetration test assesses an organization’s infrastructure from the inside. It involves simulating an attack by an employee who already has access to the organization’s network or a hacker who has managed to obtain access to the internal infrastructure.
Web application penetration testing
The objective of this type of test is to identify security flaws in websites or e-commerce platforms. Testers examine web apps for vulnerabilities such as SQL injection, cross-site scripting (XSS), and insecure APIs.
In this type of test, a web application is an entry point into the customer company’s infrastructure. A penetration tester could be given information to log in to the application or even provided with administrator rights. This helps the tester focus on searching for vulnerabilities that a threat actor with access to the application could use.
Web application penetration testing is conducted according to the best global practices (such as the OWASP Testing Guide) and is among the quickest ways to find vulnerabilities on both the client and server sides of web applications.
Web application penetration testing is especially suitable for companies that are at the early stages of their development and actively growing. It is an effective way to maintain security at times when a web application is being updated.
Social engineering penetration testing
Humans are often the weakest link in the security chain. Penetration testers can use social engineering to trick employees into revealing sensitive information. The distinct nature of this type of check is that social engineering techniques rely on human psychology rather than just technical aspects like other types of tests.
Wireless penetration testing
Vulnerabilities in corporate Wi-Fi networks often enable threat actors to gain access to resources and critical parts of IT infrastructure. A wireless penetration test reveals weak spots in Wi-Fi network configurations and shows the potential consequences of exploiting such vulnerabilities.
This type of penetration test usually requires that a specialist be physically located within the area covered by the organization’s Wi-Fi. However, vulnerabilities can be detected and used outside the office, and in some cases even remotely.
Our Penetration Testing methodology – best practices for effective Penetration Testing
There are three types of penetration testing methods we use depending on what information is initially available to the penetration tester: , Gray Box, and Black Box.
1. White Box implies that, before starting the test, the penetration tester is fully informed about how the target organization’s internal infrastructure works, how data is processed, and how applications function.
- Gray Box implies that the penetration tester is provided with a non-privileged account and information about how the network infrastructure is structured. This type of test helps specialists focus on the systems that are the most vulnerable, the most high-risk, and the most high-value.
- Black Box implies that the penetration tester is not familiar with the target system and creates the test without any prior knowledge of the customer’s network, internal processes, or specifics about how their applications work. This method is the closest to a real-life attack and requires the penetration tester to have excellent technical skills.The key disadvantage of all three methods is that if the pentester is unable to penetrate the perimeter, any vulnerabilities in internal services will not be detected or fixed.
Phases of penetration testing
How to do penetration testing depends on its objective which is to breach the customer company’s infrastructure. However, the work of pen testers is more than just that. Thus, a penetration test can be divided into six stages.
1. Planning
The first stage of a penetration test involves assessing the test’s scale and aims. The customer and contractor should agree on the testing logic, expectations, and objectives.
Depending on the type of test, it must be decided whether the penetration tester needs to be on site. In addition, this stage involves determining the testing method as well as the terms of reference and tasks for the specialist.
2. Reconnaissance
The penetration tester gathers information in open sources, including social media, mass media, the target organization’s public website, and network and domain names.
For example, social media platforms are a useful source of information about employees. Knowledge about employee names and their roles at the organization can help create a list of email addresses for a phishing attack or identify network administrators.
In some cases, this stage can be skipped and the specialist works only with specified data and entry points to the infrastructure. This makes it possible to conduct precision checks of the customer’s security systems. Group-IB has released a Reconnaissance Handbook for organizations to understand the required framework and strategies.
3. Vulnerability analysis
This stage starts with scanning and analyzing the customer company’s IT assets, after which the penetration tester begins searching for and analyzing vulnerabilities. At this stage, the objective is to detect vulnerabilities that can be leveraged to penetrate the company’s infrastructure.
Penetration testers can discover vulnerabilities manually by analyzing the results of the previous stage, or they can use an automated vulnerability scanning tool. Companies tend to use their own sets of programs and methods for searching for vulnerabilities. Apart from the publicly available software, these often include proprietary purpose-built programs.
4. Exploitation and post-exploitation of vulnerabilities
At this stage, the specialist’s goal is to access the target system by using loopholes identified in earlier stages. The penetration tester attempts to find an entry point and then searches for resources that can be accessed via that entry point.
Post-exploitation implies using information obtained as a result of exploiting vulnerabilities to further the attack and access other subnets and data storage systems. This information could include additional routers, server names, network services, and installed applications.
5. Result analysis and reporting
A penetration testing report describes the results and findings of the test. The information it contains helps the customer make technical and business decisions.
A good penetration testing report describes the attack chains involved and ranks any discovered vulnerabilities according to their risk level. Specialists also include screenshots of actions they have taken and detailed descriptions of each attack stage. A pentester’s task is not just to demonstrate vulnerabilities and the risks they entail, but also to explain how the vulnerabilities can be eliminated and what should be done to ensure that they do not occur again.
A penetration testing report usually has the following sections:
- General information about the project and findings
- Information about the project
- General conclusions and recommendations
- Testing program and methodology
- External penetration testing methodology
- Risk-rating methodology
- Stages of penetration testing
- Collection of information about network services
- Search for and analysis of vulnerabilities on external and/or internal perimeters
- Exploitation and post-exploitation of vulnerabilities
- Appendices
- Screenshots, tables, and other material
The following information in the report should be noted:
- Specific vulnerabilities discovered
- Confidential data accessed
- The time during which the pentester could remain unnoticed in the system
The report should have a clear executive summary and contain both technical and business-related conclusions.
In some cases, it might be required to conduct an in-person presentation about the penetration test, in which case it is best to ensure that the contractor’s specialists are physically located in the customer’s region.
6. Following recommendations
A penetration testing report should list recommendations in a user-friendly format that includes tables, screenshots, photos, and text descriptions. This will help the customer’s information security team use the report as a basis for improving their security systems.
After receiving a penetration testing report, organizations tend to recreate and check attack chains. They then make the necessary changes using public sources, employees’ knowledge, and the penetration tester’s recommendations. As a final step, the pentester usually completes a follow-up assessment of how their recommendations have been implemented.
Industries that benefit from Penetration Testing
Penetration testing is not confined to one industry; its applications span across various sectors, each with its unique challenges and security requirements. Let’s explore some key industries that reap significant benefits from regular penetration testing.
1. Financial Services
Banks, credit unions, and financial institutions deal with sensitive customer data and high-stakes transactions daily. A security breach in this sector could lead to severe financial losses and regulatory penalties. Penetration testing helps ensure robust protection against sophisticated cyber threats and reinforces trust among clients. In fact, Group-IB offers cybersecurity services specialized for financial services companies.
2. Healthcare
Healthcare organizations store vast amounts of personal health information (PHI), making them prime targets for cybercriminals. Regular penetration testing helps these organizations secure patient data, maintain compliance with regulations like HIPAA, and ensure operational continuity.
3. Retail and E-commerce
Retailers and e-commerce businesses are frequent targets for cyber attacks due to the volume of transactions and sensitive customer data they handle. Penetration testing safeguards payment systems, protects customer information, and builds consumer confidence. With Group-IB’s specialized services, you can protect your retail and e-commerce companies from cyber attacks.
4. Government and Public Sector
Government agencies are custodians of critical data and infrastructure. Penetration testing in this sector is vital for national security, protecting public services, and ensuring that confidential information remains secure. Thus, it is crucial for Government agencies to have a solid cybersecurity solution in place.
5. Technology and Telecommunications
Companies in the technology sector rely on advanced systems and networks to deliver their services. The telecommunication industry breathes data, which makes it important for companies to create an efficient cybersecurity defense. Penetration testing helps Telecom businesses identify potential vulnerabilities in their products and systems, ensuring the security and reliability of their offerings.
6. Energy and Utilities
Energy companies and utility providers face unique challenges in securing critical infrastructure. Penetration testing in this industry helps prevent disruptions that could have wide-reaching implications for public safety and national security.
Across these industries, understanding what is penetration testing and its practical benefits is essential. Each sector benefits from tailored testing approaches that address its unique risks and regulatory requirements.
How often should businesses conduct Penetration Testing?
Determining how often should businesses conduct penetration testing depends on several factors, including the size of the organization, the nature of the data processed, and regulatory requirements. However, as a best practice, organizations should consider the following guidelines:
Regular Testing Cycle
For many organizations, conducting penetration tests at least once a year is advisable. Annual tests ensure that emerging vulnerabilities are promptly addressed and that the security posture remains strong over time.
Following Major Changes
Any significant change in the network infrastructure, deployment of new systems, or substantial software updates should trigger an immediate penetration test. This approach ensures that new vulnerabilities introduced by changes are promptly identified and remediated.
After a Security Incident
If your organization experiences a security breach or an attempted cyber-attack, it is crucial to perform a penetration test afterward. This helps determine the extent of the vulnerability exploited and ensures that all potential vulnerabilities have been patched.
Compliance and Regulatory requirements
Compliance with regulatory standards is a critical component of any cybersecurity strategy. Penetration testing plays a vital role in ensuring that organizations meet legal and industry-specific requirements. When asking what is penetration testing, it is important to note that one of its major benefits is helping organizations adhere to regulations such as:
- PCI-DSS: Requires regular security assessments and penetration testing to protect payment card data.
- HIPAA: Mandates that healthcare organizations secure patient data, with penetration testing serving as a key tool in risk management.
- GDPR: Emphasizes the protection of personal data for EU citizens, with regular testing ensuring compliance with data protection principles.
Regular penetration testing not only ensures that you meet compliance standards but also builds a strong defense system that can adapt to evolving regulatory requirements. This proactive approach demonstrates due diligence and a commitment to protecting sensitive information.
Choosing the right Penetration Testing provider
During a penetration test, the contractor obtains information about vulnerabilities in the customer organization’s infrastructure. If this information were to get into the wrong hands, it could mean serious consequences for the company’s security. To prevent such situations, it is crucial to prepare for a penetration test thoroughly.
Check reviews by the expert community
It is important to check reputation of the penetration testing company has among the professional community and non-profit organizations to ensure that it has proven experience in carrying out high-quality penetration testing.
Professional certificates and publicly available references issued by major companies add to the credibility of the testing company.
Hire certified specialists
A security certificate issued by an authoritative organization guarantees that the penetration testers will not subsequently use what they find out about the system for malicious purposes and that all the data that the penetration testing company receives will be stored securely and will not be leaked by the contractor.
In addition to the penetration tester being able to confirm their qualification, it is important to make sure that the contractor company handles data in accordance with international standards such as ISO-27001 and ISO-9001, which would confirm that it uses high-quality and secure processes.
Sign a non-disclosure agreement (NDA)
When signing a contract with a company that will conduct a penetration test, it is important to pay attention to confidentiality aspects set out in NDAs and service agreements.
Does Group-IB provide penetration testing services?
Yes. Group-IB experts successfully completed 1,000+ security assessment projects, including penetration testing. Our specialists have 21 international professional certificates, and our processes comply with ISO-27001/9001 international standards, which guarantees the security of your confidential data. Group-IB is well known for its cybersecurity services helping you optimize your IT infrastructure for any potential cyber threat by implementing a secured and effective penetration testing and threat intelligence solution. For more information contact us today.
Frequently Asked Questions (FAQs)
1. What is the typical duration of a penetration test?
The duration of a penetration test varies depending on the scope and complexity of the target system. A standard test might take anywhere from a few days to several weeks. The time frame is influenced by factors such as the number of systems tested, the depth of analysis required, and whether the test includes social engineering or physical security assessments.
2. How often should a company conduct penetration testing?
The frequency of penetration testing depends on several factors, including the industry, regulatory requirements, and changes to the IT environment. Generally, the recommended interval to conduct a penetration test is at least once in a year. However, after significant system updates or following a security incident, additional testing is advisable to ensure that all vulnerabilities are promptly addressed.
3. Will penetration testing disrupt our business operations?
A well-planned penetration test is designed to be minimally disruptive. Testing is usually scheduled during off-peak hours and conducted in a controlled environment to avoid any negative impact on daily operations. Clear communication with your IT and security teams is crucial to ensure that testing is seamless and safe.
4. What kind of report will we receive after the test?
After the penetration test, Group-IB provides you with a comprehensive report detailing all identified vulnerabilities, the methods used to exploit them, and actionable recommendations for remediation. The report is designed to be clear and understandable, enabling you to address security gaps effectively. It will also outline what is the primary goal of penetration testing and provide insights into how to do penetration testing in a structured manner.
5. How does penetration testing help with regulatory compliance?
Penetration testing is a vital component of regulatory compliance frameworks such as PCI-DSS, HIPAA, and GDPR. By identifying vulnerabilities and ensuring that systems are secure, penetration testing helps organizations demonstrate their commitment to protecting sensitive data and maintaining robust security measures. This proactive approach is essential for avoiding non-compliance penalties and reinforcing trust with clients and regulators.