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What is Penetration Testing and Which Test Applies to Your Business?

What is Penetration Testing

Penetration tests which are also known as the Pen Test are tests or assessment methods to check the organization's cybersecurity safety. It is a kind of ethical hacking wherein the security professionals ethically hack into your system to determine security lapses or loopholes and accordingly address the identified weaknesses in the system.

Penetration testing is a simulation of real-world attacks in a controlled environment that helps uncover vulnerabilities that will not actually damage your assets but just expose the weaknesses.

Objectives of Pen Test

While we know that the Pen test helps expose weaknesses in a system, let us understand how conducting a pen test helps. 

  • Identify potential vulnerabilities through a detailed analysis. 
  • Simulate cyber-attacks by penetrating vulnerable systems, applications, and services both externally and internally using various tools. 
  • Gain access to sensitive data and/or systems to expose gaps in the system. 
  • Potentially quantify the impact on a breach such as the type of data and the amount of data loss that can occur in case of an actual attack.

Type of Approach to Penetration Testing

Penetration testing can be tailored for a variety of products, requirements, applications, and situations. So, before selecting a vendor, it is essential to determine which approach is the most effective for you. To learn about tests that are appropriate for your business first let us understand the different approaches to Pen Tests.

Black Box

In black-box testing, the tester becomes an ethical hacker, with no knowledge of the internal target system. The Testers are not provided with any architecture diagrams or source codes or given any access to the systems. The ethical hacker is required to hack the system from an external network to determine the vulnerabilities in a system that are exploitable from outside the network.

In other words, the ethical hacker will have as much access and visibility into the system as an outsider or a Blackhat hacker with no special privileges or knowledge of the system. Due to the very nature of the assessment, unless the hackers are able to identify some core vulnerability, such a test is superficial by nature and will not uncover vulnerabilities in the system which are accessible only with special access such as a login ID and password.

White Box Tests

White-box testing also known as static testing, clear-box, open-box, auxiliary and logic-driven testing adopts the opposite approach to the black box testing.  In this case, the testers are given full access to source code and architecture documentation for determining vulnerabilities.

But one of the major challenges in this type of test is that the tester must literally sift through the massive amount of data to identify weaknesses or vulnerabilities which makes it the most time-consuming penetration testing. With the development of specialised software, this manual process has been automated to a large extent. White-box penetration testing includes determining both internal and external vulnerabilities, making it the best type of testing for a comprehensive security check of the IT environment.

The only problem with this testing is that a few vulnerabilities are “activated” only when the code is run in an environment and when the vulnerabilities or peculiarities of the environment creates vulnerabilities in the application too… plus, most importantly, white box testing doesn’t include Logic errors.

Grey Box Tests 

The grey-box tester has the access and knowledge of a user with elevated privileges on a system. They have some knowledge of a network’s internal system including design and architecture documentation and an account internal to the network. Grey box testing provides a more focused and efficient assessment of a network’s security than a black-box assessment.

The pen tester focuses the assessment efforts on systems with the greatest risk and value rather than spending time in guessing its architecture and logic flow. This proves to be the most efficient since most of the time in the wild, the hacker would have access to compromised credentials rendering a plain black box assessment as grossly undermined.

Types of Penetration Test

Internal test- An internal penetration test involves an ethical hacker mimicking the strategy of a hacker who might have taken preliminary access to the network through a malicious act, or a disgruntled employee looking to escalate further intrusion. The end target is ultimately to hack the system and get hands-on confidential data from within the network itself.

External test- An 'external' pen test involves an ethical hacker process wherein the hacker hacks the organization’s network remotely using controlled and agreed on ethical hacking techniques. This is typically done to accurately simulate a targeted attack from malicious parties on your network.

Web application test- A web application penetration test, involves determining security issues that might be caused due to insecure development, design, or coding. The test helps to identify potential vulnerabilities in your websites and web applications, including CRM, extranets, and internally developed programs. 

Social engineering test- This type of test is another important type of penetration testing that helps verify the “Human Network” of an organization. This pen test involves simulating a potential attack carried out towards an employee of the company who could attempt a breach. Social engineering is highly prevalent and is certainly an organization's greatest risk. I will not go into this much since I have already written other articles in this category as shown below with their links.


Black-box, white-box and grey-box pen tests are all different approaches to simulating a hack that attacks the network and identifying vulnerabilities. Ideally, most penetration tests would be black box since it is the one that most closely resembles a real-time hack.  However, the desire to detect and remediate vulnerabilities inside the perimeter has led to the demand for grey-box and white-box tests too.

Similarly, the type of Pen Test depends on the application, the requirement of the system, and business needs in general. So, coming to our question of which test and approach is appropriate for your business ... it all depends on the type of business, application in question, and the purpose of conducting the test that will help you figure which test is most suitable. Ideally hiring a professional will make it easier for you to decide which test is the most suitable for your security systems.

Author Bio:

Narendra Sahoo (PCI QSA, PCI QPA, CISSP, CISA, CRISC) is the Founder and Director of VISTA InfoSec, a foremost Company in the Infosec Industry. He holds more than 25 years of experience in the Information Technology Industry and has expertise in Information Risk Consulting, Assessment, & Compliance services.

His company, VISTA InfoSec, has been instrumental in helping top multinational companies achieve compliance in areas such as PCI DSS, PCI PIN, SOC2, GDPR, HIPAA, MAS TRM, PDPA, PDPB to name a few. Mr. Sahoo for his extensive contribution to the industry has also been inducted into the CSI – Hall of Fame for his significant contributions to the fraternity and has also been awarded the “Crest of Honour” by the Indian Navy.