Introduction: What is a Penetration Tester?

A penetration tester legally and ethically hacks into an organization’s digital assets to find vulnerabilities. This is why a Pen Tester is also called an Ethical Hacker or Assurance Validator.

Pen testing involves simulating various attacks into networks, computer systems, and web-based applications to validate an organization’s security posture and detect weaknesses that a potential cybercriminal could exploit.

The pen tester's role is critical when building a cybersecurity team and is a part of the Red Team. This professional uses techniques like footprinting and reconnaissance to help businesses identify flaws and weaknesses in an active system and expose critical issues that must be resolved.

Performing a cybersecurity penetration test helps organizations evaluate whether their system is robust enough to withstand attacks from unauthorized personnel.

If this cybersecurity specialization interests you, our guide delves into everything you should know about the role.

As a pen tester, you can work in-house with permanent employers, functioning in an internal cybersecurity team. Or you can work for cybersecurity outsourcing companies that provide services to clients. The latter is the most trusted option, as independent Pen Testers are more likely to be objective and detect insider threats.

We will cover the benefits of pen testing, the duties of a penetration tester, and the tools and techniques you’ll need in this role.

Cybrary provides a guided pathway to becoming a Penetration Tester. You will learn from industry-recognized Pen Testers through hands-on preparation and real-world scenarios to footprint and ethically break into a company. Become a Pen Tester now.

What Does the Penetration Tester Role Entail?

To catch a thief, you must first think like one. This is the reality of a Penetration Tester’s duties. Your day-to-day activities will involve conducting assessments and running tests to find vulnerabilities that a malicious hacker might exploit.

Although responsibilities will differ depending on the organization, industry, and the threats they face, a penetration tester's core duties are:

  1. Develop strategies, scripts, and methodologies for the current project, including setting up required tools.
  2. Gather and use Open-Source Intelligence (OSINT) to analyze publicly available data for intelligence.
  3. Conduct tests and simulations on targeted computer systems, networks, web, and applications to look for vulnerabilities.
  4. Examine results to develop a holistic analytic view of the computer system within the environment it operates.
  5. Create reports and recommendations from the findings of the pen test.
  6. Work with other team members and provide technical support to the Chief Information Security Officer (CISO) in remediating assessment findings.
  7. Improve Digital Forensics and Incident Response (DFIR) efforts.
  8. Conduct physical security assessments of network device security and server systems to find issues such as vandalism, temperature, and natural disasters.
  9. Perform security audits to evaluate if the organization conforms to established criteria and compliance regulations.
  10. Analyzing cybersecurity policies and procedures to determine their effectiveness and provide recommendations for improvement.

The Benefits of a Penetration Tester to an Organization

Software and systems were designed to eliminate potentially dangerous security weaknesses. Cybersecurity penetration testing provides insight into how well that goal was met.

As an aspiring Pen Tester, here are the benefits an organization will expect from you:

  1. Detect vulnerabilities in systems, networks, servers, and other digital assets in the security infrastructure.
  2. Determine the robustness of security controls.
  3. Support compliance with security and data privacy regulations such as HIPAA, GDPR, CCPA, and PCI DSS.
  4. Provide senior management and C-suite executives with quantitative and qualitative examples of the current security infrastructure and budget priorities.
  5. Determine organizational risk appetite and risk tolerance
  6. Ensure the organization maintains customer trust, reputation, and credibility by preventing data leaks.
  7. Provide assurance and ensure a system's security features, procedures, and architecture accurately enforce the security policy.
  8. Help the cybersecurity team, especially the Incident Response unit, learn how to handle any cyber-attack from a malicious entity.

The proactive nature of Penetration testing allows employers to avoid public fallout and loss of consumer confidence from cyber-attacks. It also helps companies improve their security measures, facilitating quicker business continuity after an attack.

Types of Pen Testing a Penetration Tester Will Use

Penetration testing methodology is divided into three types: white-box assessment, black-box assessment, and gray-box assessment.

  1. White-Box Assessment: White box penetration testing, also known as crystal or oblique box pen testing, involves sharing a wide range of network and system information with the tester, such as network maps, credentials, Schema, Source code, OS details, IP address, and so on. Not only does this save time, but it can also reduce costs. White box pen tests are typically considered an attack simulation by an insider threat.
  2. Black Box Penetration Testing: In black box penetration testing, the tester has no knowledge of the systems they are going to test. The tester is not given any information. A tester, for example, only knows what the expected outcome should be, not how the outcome arrives. As a Penetration Tester, this type of security testing means you’ll follow the approach of an unprivileged attacker from the first access to execution and exploitation. While it is the most realistic type of pen testing that demonstrates how an external threat would target and compromise company assets, it can also be costly.
  3. Gray Box Penetration Testing: Also known as translucent box testing, the information shared with you as a Penetration Tester is partial or limited. For example, login credentials. You can think of this as an attack by an external hacker who gained unauthorized access to sensitive network infrastructure information. Gray Box testing helps organizations understand the level of access a privileged user has and the potential harm they can cause. In real-world scenarios, an attacker will perform surveillance on the target system or network to gain insider knowledge. However, this type of security testing balances efficiency and authenticity as it eliminates the time-consuming reconnaissance stage.

Areas of Penetration Testing

A comprehensive penetration test is typically done in the following areas:

1. Network Security Testing

The goal of a network pen test is to detect the most exposed vulnerabilities and security flaws in an organization’s network infrastructure before they are exploited. This includes firewalls, servers, routers, switches, workstations, computers, printers, remote access systems, etc. Network pen tests will protect the organization from network-based attacks like DNS, IPS/IDS Evasion, Firewall Misconfiguration, Firewall Bypass, SSH attacks, and Man in the Middle (MITM) attacks.

2. Mobile Application Penetration Testing

As a Penetration tester, you will identify flaws in application binaries running on mobile devices and the respective server-side functionality. It detects, authenticates, authorizes, and monitors data leakage issues. To plan a pen test, testers must first understand the type and version of the mobile app.

3. Client-Side Pen Test

Conducting this pen test allows businesses to protect themselves and their customers against cyber-attacks like clickjacking, form hijacking, cross-site scripting (XSS), and HTML injection.

4. Web Application Pen Testing

Web application penetration testing is used to identify security flaws or vulnerabilities in web-based applications. It employs various penetration techniques and attacks to gain access to the web application itself. As a pen tester, you will evaluate the effectiveness of security controls and look for hidden security flaws, attack patterns, and any other possible security gaps that could lead to a web app compromise.

5. Wireless Penetration Testing

This involves testing all devices connected to a company’s WiFi. A wireless penetration test covers desktops, laptops, mobile phones, tablets, and similar devices. As a Penetration Tester, you will be required to be on-site to carry out wireless pen tests, as you must be within range of the signal to access it.

6. Social Engineering Pen Test

Social engineering aims to trick users into sharing sensitive information such as banking details, phone numbers, email addresses, login credentials, etc. Conducting this pen test helps organizations prevent social engineering attacks like phishing, DNS spoofing, dumpster diving, scareware, and watering hole attacks.

Other areas you can conduct pen tests include:

  • Containers
  • Cloud environments
  • Embedded devices such as the Internet of Things (IoT)
  • Application Programming Interfaces (APIs), and
  • Continuous Integration and Continuous Deployment (CI/CD) pipeline.

The 5 Phases of Penetration Testing and Essential Tools for a Penetration Tester's Toolkit

Penetration Testers need several tools and techniques to perform their duties. But there is no universal pen-testing tool. Different targets will require different Pen Testing toolkits for port scanning, vulnerability scanning, network penetration, password cracking, and WiFi break-ins.

Since there are five phases of Pen testing, the tools a Penetration Tester needs are also broadly classified into the following:

1. Footprinting and Reconnaissance Tools

Reconnaissance is the first phase of penetration testing. During this phase, the tester gathers as much information about the target system as possible, such as network topology, operating systems and applications, user accounts, and other necessary details. The goal is to collect as much information as possible so that the tester can devise an effective attack strategy.

The tools needed for this include Search Engines like Google and Shodan, FireCompass, Recon-NG, Maltego CE, HTTrack, theHarvester, Spiderfoot, Censys, etc.

Learn footprinting and reconnaissance and how to use these tools on Cybrary.

2. Vulnerability Scanners

After gathering relevant data, Pen Testers use different tools to check network traffic and find open ports on the target system. Penetration testers must identify as many open ports as possible because open ports are potential entry points for attackers.

Examples of vulnerability scanners include Nessus, Burp Suite, nMap, Nexpose, and OpenVAS. Cybrary offers real-world vulnerability scanning challenges that help you use tools like OpenVAS and Nessus.

3. Vulnerability Assessments

Vulnerability assessment is the third penetration testing phase, in which the Pen tester uses all of the data gathered during the reconnaissance and scanning phases to find possible security flaws and assess whether they can be exploited.

Most Vulnerability Scanners can be used for Assessments, including Nessus, OpenVAS, and Burp Suite. Others include Wireshark, Dectify, and Qualys Guard.

Proxy tools are also used here. Some of them are Burp Proxy in Burp Suite, Paros Proxy, OWASP Zap Proxy, Fuzzers like Wfuzz, and Burp Intruder.

4. Exploitation Tools

Once vulnerabilities have been discovered, it is time to exploit them. During this penetration testing phase, the penetration tester attempts to gain access to the target systems and exploit the known vulnerabilities.

This is typically done by simulating real-world attacks with tools like Metasploit, BeEF, Armitage, Aircrack-ng, and SQLMap.

After exploitation, the Pen Tester moves on to post-exploitation. The Post Exploitation phase aims to identify the value of the compromised system or machine and maintain access to it for future use.

Tools used in the post-exploitation phase help you, as a Pen Tester, check for common misconfigurations that can allow an attacker to escalate their privileges. Examples of post-exploitation tools include Metasploit, Netcat, nMAP, Hping3, BeRoot, and Burp Suite.

5. Reporting Tools

The last phase is to document the findings of your penetration test. This report can be used to fix the vulnerabilities found and improve the organization’s security posture. Examples of tools that can help you document your activities clearly include Dradis, Metagoofil, Magic Tree, Faraday IDE, and Serpico.


Ultimately, the goal of a Penetration Tester is to identify security weaknesses in an organization’s network, machine, systems, or software. This will help to improve the security posture and prevent potential cyber-attacks.

If the Penetration Tester role sounds interesting, you can become one in record time through Cybrary’s learning resources. Whether you want to start afresh as a Pen Tester or advance your Pen Testing career, Cybrary offers theoretical and hands-on training to help you skill up.

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