What Is a Penetration Tester? Finding Security Issues

By Dr. Matthew Loux and Bryce Loux  |  02/24/2026

A cyberattack can come to an organization from almost any direction. Some cyberattacks come from internal employees who bypass existing security measures; they steal valuable data for resale, revenge, or espionage. Other attacks might come from an external threat actor, who uses various techniques and tools to bypass network security.

To reduce their vulnerability and protect proprietary or client data, organizations often hire penetration testers (also known as pen testers). A penetration tester is a cybersecurity professional who specializes in simulating cyberattacks on computer systems, networks, and applications. The primary objective of pen testers is to identify security problems before malicious actors can exploit them using various penetration testing tools.

Pen testers also report their findings and recommend security improvements to organizational leaders. Consequently, leaders can then take action and use new security features to protect themselves from liability and a loss of brand reputation.

The Value of a Penetration Tester

By proactively testing an organization’s digital assets, penetration testers help companies understand where their defenses and vulnerability management may fall short. Their work is crucial in proactively defending against cyberattacks and helping organizations to build more resilient systems, so that attackers cannot gain access and wreak havoc. These security professionals provide actionable recommendations to strengthen an organization’s information security posture and protect sensitive information.

Daily Responsibilities of a Penetration Tester

Sophisticated cyberattacks are a persistent threat. Consequently, penetration testers spend much of their time conducting vulnerability assessments, scanning networks, and analyzing network structures and protocols to uncover potential weaknesses. Their work may include:

• Reviewing file shares
• Performing privilege escalation
• Ensuring lateral movement
• Pivoting
• Conducting post-exploitation activities

Beyond technical testing, penetration testers frequently communicate with clients, support senior leadership, and participate in security debriefs or sales calls. A penetration tester’s job may also involve:

• Documentation of simulated cyberattacks – performing simulated cyberattacks to evaluate how well systems can withstand attempted breaches and creating documents
• Reporting – combining findings into detailed reports, calculating risk analyses, and providing recommendations to strengthen weaknesses
• Client communication – explaining complex findings to non-technical stakeholders

A penetration tester's skills are varied. In this field, communication skills, calmness under pressure, problem-solving skills, and teamwork are just as important as technical skills.

Pen testers may work in conjunction with information security analysts, security engineers, and computer engineers. This work helps to ensure proper defenses and rapid event management when an attack occurs and an incident response is needed.

The Steps Pen Testers Use to Check for Vulnerabilities

Successful penetration testers typically follow a step-by-step approach when checking for vulnerabilities:

1. Planning and reconnaissance – Penetration testing begins with defining project scope, understanding the target system and network infrastructure, and gathering information about security controls and potential vulnerabilities.
2. Vulnerability scanning – Penetration testers use specialized automated tools to scan a target for potential vulnerabilities, such as outdated software, misconfigurations, or weak passwords, that could impact data security.
3. Exploitation – Once vulnerabilities are identified, penetration testers attempt to exploit them to gain unauthorized access or escalate privileges within the system, simulating real-world attack scenarios.
4. Post-exploitation – After gaining access, testers analyze a system to identify additional security issues. They assess the impact of the breach and determine how far an attacker could realistically progress.
5. Reporting – All findings are thoroughly documented, including the details of exploited vulnerabilities, the methods used for the attack, and the potential risks. Penetration testers also provide clear, actionable remediation recommendations to ensure network and computer security.
6. Remediation – The final step involves working with an organization to implement new security measures, patch vulnerabilities, and strengthen security controls to reduce the likelihood of future attacks.

Ethical Hacking and Penetration Testing

Ethical hacking and penetration testing are closely related, but they are not identical. Ethical hacking encompasses a wide array of security assessments, performed with pen testing tools and an organization’s permission to improve network security. Ethical hackers' work includes:

• Social engineering
• Physical security assessments
• Advanced network and application testing

Penetration testing, on the other hand, involves a more focused, structured process. Penetration testing zeroes in on finding and safely exploiting security vulnerabilities in a targeted environment. It focuses on systems, networks, applications, and devices.

Common penetration tester tasks may include:

• Scanning networks and identifying open ports to bypass security systems
• Exploiting security vulnerabilities in operating systems
• Testing multi-factor and single-factor authentication mechanisms to identify security flaws
• Conducting web application penetration testing

Penetration testing is considered a specialized subset of ethical hacking. It often forms part of a larger red team operation that simulates real-world attacks, and it provides useful security feedback from an adversary’s perspective.

Red and Blue Testing Teams

During a simulated attack on an organization, pen testers can work on red or blue pen testing teams. Red teams act as vulnerability analysts and serve as the attackers, who seek to pass through an organization's cyber defenses. Blue teams are the defenders, who identify, assess, and respond to the simulated attack in real time.

Cybersecurity company CrowdStrike recommends that teams follow the “1-10-60 rule” when assessing security risks. According to CrowdStrike, "organizations should be able to detect an intrusion in under a minute, assess its risk level within 10 minutes, and eject the adversary in less than one hour."

Cloud Security and Penetration Testing

As more organizations move their operations to the cloud, cloud security and penetration testing have become critical components of a robust cybersecurity strategy. Cloud penetration testing focuses on identifying security vulnerabilities in cloud-based infrastructure, applications, and data storage.

Penetration testers’ work involves using a variety of tools and techniques – such as network scanning, vulnerability assessment, and exploitation – to evaluate cloud environments. The goal is to identify potential security flaws and provide actionable recommendations to enhance the security posture of cloud-based systems. This process is essential for:

• Protecting sensitive data
• Ensuring compliance with security regulations
• Maintaining customer trust in cloud services

Cloud penetration testing jobs require an advanced knowledge of cloud security protocols, cloud infrastructure, and the unique challenges posed by cloud-based applications. Skilled penetration testers must understand how to:

• Navigate complex cloud environments
• Assess security controls and network protocols through security testing
• Identify vulnerabilities that could be exploited by attackers

By proactively testing cloud systems, organizations can stay ahead of emerging threats and ensure their cloud security measures are effective and up to date.

The Bachelor of Science in Cybersecurity at APU

For adult learners who want to develop their penetration testing skills, American Public University (APU) has an online Bachelor of Science in Cybersecurity. Students who enroll in this degree program can take courses in red and blue team security, hardening operating systems, and cyber warfare. Other courses involve scripting languages, cybersecurity, networking concepts, and IT security planning and policy.

This bachelor's degree in cybersecurity has five concentrations to suit the academic and professional goals of students. These concentrations include:

• General
• Digital forensics
• Critical infrastructure
• Privacy and surveillance
• Wireless and mobile security

For more details about this B.S. in cybersecurity, visit APU’s information technology degree program page.