Penetration Testing For Beginners

Penetration testing is the testing of a computer system, web application, and network to find security weaknesses that an attacker could utilize. This kind of testing can be automated or performed manually. The process involves collecting information about the target before the testing, identifying the possible entry points, attempting to break in for virtual or for real, and reporting back the findings.

The main aim of a pen test is to identify the weak spots in a security posture of an organisation, as well as to measure the acceptance of the security policy, test the awareness of security and determine whether the organisation would be subject to security disasters.  

A penetration test also highlights weaknesses in a company’s security policies.

The reports that are generated by a penetration test provides feedback. The reports help the application developers to create more secure applications.

Steps to Initiate Penetration Testing

Step 1) The Planning phase

  1. Scope and strategy of an assignment are determined.
  2. The security policies, standards are used for defining scope.

Step 2) The Discovery phase.

  1. Collect information about the system, including data in the design, usernames, and even passwords. 
  2. Scan and Probe into the ports
  3. Check for vulnerabilities of the system

Step 3) The Attack Phase

  1. Find exploits for various weaknesses. You won’t get necessary security Privileges to exploit the system

Step 4) The Reporting Phase

  1. The report must contain detailed findings.
  2. Risks of weaknesses found and their Impact on business.
  3. Recommendations and solutions.

Penetration Testing Methods

External testing

It targets the assets of the company that is visible on the internet, For example, email and domain name servers (DNS) and the web application itself, the company website. The main aim is to gain access and extract valuable data.

Internal testing

A tester with access to an application behind the firewall simulates an attack by an insider. This is not necessarily affecting a rogue employee. A typical scenario can be an employee whose credentials were stolen.

Blind testing

A tester is only given the name of the enterprise that is being targeted. It offers security personnel a look into how an actual application would take place.

Double-blind testing

The security personnel does not know the attack. They would not have any time to shore up their defences before a breach.

Targeted testing

Both tester and security personnel work together and keep each other apprised of their movements. It is a training exercise that provides the security team with real-time feedback from a hacker’s point of view.


  • Testing enables a bold security approach.
  • It allows the study of real risks and having an accurate representation of a company’s IT infrastructure security posture at the given time.
  • It helps investigate a data breach or the network intrusions to discover any leads to the leakage of data or theft of intellectual property.
  • It allows the collection of information about the system to learn and perhaps even come across some internal reports on active hackers.
  • It can find both unknown and known flaws and exploit security vulnerabilities, which can be identified and fixed before they are used in a much more effective way with automated tools.
  • It can validate the efficacy of the defensive mechanisms far beyond the analysis provided by a vulnerability assessment in identifying the weaknesses.
  • It gives the possible ways to test a system with attacks that are as close as possible to real-world incidents thanks to the work of professionals that think and strike as most malicious hackers would.


  • It is doubtful that a penetration test will find all the security issues or will solve all the problems when scanning for weaknesses and generating an automated report.
  • It takes a tester more time to inspect the system to identify the attack than doing a weakness assessment; being the test scope is more significant. His/her actions can also be disruptive for business activities as they mimic a real attack.
  • It is high-labour intensive, and it can represent an increased cost, and few organisations might not be able to allocate a budget for this. This is true when a firm is hired to carry out the task.
  • It gives a false sense of security. In most cases, testing is known to company security teams who are ready to look for threats and are prepared to defend. Real attacks are unannounced and, above all, unexpected.

Types of Penetration Testing

Following are the essential types of penetration testing:

  • White Box Penetration Testing
  • Black Box Penetration Testing
  • Grey Box Penetration Testing

White Box Penetration Testing

This is comprehensive testing, where a tester is provided with a lot of information about the systems and network such as Source code, Schema, OS details, IP address, etc. It is considered as a simulation of an attack by the internal source. It is also called structural, glass box, clear box, and open box testing.

White box penetration testing examines the code coverage and does data flow testing, path testing, loop testing.


  • It ensures that independent paths of a module have been exercised.
  • It provides all logical decisions that are verified along with their true and false value.
  • It discovers the errors and checks the syntax.
  • It finds the design errors that occur because of the difference between the logical flow of the program and the actual execution.


  • The attack lacks realism.
  • The tester thinks differently than a non-informed attacker.

Black Box Penetration Testing

In this testing, the tester has no idea about the system he/she is going to test. He/she is interested in collecting information about the network or system. E.g., in this type of testing, a tester only knows what should be the expected output, and he/she doesn’t know how the outcome is going to be. He/she does not examine any programming codes.


  • It does not demand any specific programming language knowledge.
  • The tester verifies contradictions in the existing system.
  • The test is generally conducted from a user perspective, not the designer.


  • The test cases are difficult to design.
  • It does not conduct everything.

Grey Box Penetration Testing

In Grey Box Penetration Testing, a tester usually offers partial or limited information about the program of a system. It is considered as an attack by an external hacker who gained illegal access to an organisation’s network.


  • Tester does not require access to the source code.
  • There is a clear difference between a developer and a tester, so there is less risk of personal conflict.
  • You don’t need to offer internal information about the program functions and other operations.


  • Testers do not have access to see code.
  • Gray box testing is redundant if the application developer has run a similar test case.
  • Gray box testing is not ideal for algorithm testing.

Tools for Penetration Testing

The Network Mapper (also known as “NMAP”)

It is used for discovering the kind of weaknesses in the network environment of a business or a corporation. It can be used for auditing purposes as well. NMAP takes the raw data packets which are created 

  • What kind of hosts are available on a particular network trunk or segment
  • These hosts provide information about the services
  • Any particular host is using the versions and the types of data packet filters/firewalls

You can create a map of the network and from there, point out the significant areas of vulnerabilities that a Cyber attacker can penetrate through.

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This tool is an actual data packet analyser and network protocol which analyses the security weaknesses of the traffic in real-time. Information and data can be collected from:

  • Bluetooth
  • IEEE 802.11
  • IPsec
  • Token Ring
  • Frame Relay
  • Kerberos
  • SNMPv3
  • WEP
  • Any Ethernet-based connections
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The software developers create this suite, and the main aim is to find and exploit any security weaknesses present in the web-based applications. It consists of many tools which can root out threats such as:

  • User-Agent Faking
  • Custom headers to requests
  • DNS Cache Poisoning
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Best Companies for Penetration Testing


It is a cybersecurity service provider and a software development company. It helps their clients operating in banking, healthcare, manufacturing, and other industries to design and implement the most relevant defence for their IT environments.

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is an accurate automated scanner that identifies vulnerabilities in web applications and web APIs. It uniquely verifies the vulnerabilities proving they are real and not false positives. 

It is available as a window software and an online service.

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Indusface WAS 

It provides the manual Penetration testing bundled with an automated web application weaknesses scanner that detects and reports weaknesses based on OWASP top 10. 

The company is located in India with other offices in Mumbai, Bengaluru, Vadodara, Delhi and San Francisco, and the services are used by 1100+ customers across 25+ countries globally.

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An intruder 

It is a cybersecurity company which provides an automated SaaS solution for their clients. The powerful scanning tool is designed to deliver highly actionable results, helping busy teams to focus on what truly matters.

Intruder uses the same engine as the big banks do so that you can enjoy high-quality security checks, without the complexity. The intruder also offers hybrid penetration testing service, which includes manual tests to help identify issues beyond the capabilities of automated scans.

penetration testing


How often should we conduct a penetration test?

It depends on various factors that should be thought-through while considering the frequency to conduct penetration tests. Following are the things you should keep in mind
How frequently environment changes: Tests are often timed to changes as they are near a production-ready state.
How large the environment is: The more extensive settings are tested in phases to level the testing effort and load placed on the ground.

What are the typical costs for a penetration test?

The cost of penetration testing varies greatly.
Several factors are used for pen test pricing, including. It is essential to have a detailed scoping meeting to produce a clear understanding of the needs and develop a statement of work before engaging any penetration test. Ideally, a penetration test must be performed on a fixed-fee basis to eliminate any unplanned expenditures. The quoted fee should include all labor and required testing tools.

What should one expect from the penetration testing process?

Penetration testing is a disciplined process. A testing company should keep all the stakeholders well informed through every critical stage of the process. As a company seeking penetration testing services, one should follow in mind:
A planned, documented, and communicated approach to know what is happening and when.
A disciplined, repeatable approach should be followed.
The system must be customized to suit the environment of the business.
A defined initiation process, planning process, coordinated testing, and a collaborative delivery process to ensure accurate results and a clear understanding of remediation.

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