Fundamentals of Penetration Testing (Domain 5)
Penetration testing is one of the most hands-on and dynamic tools in a cybersecurity professional’s toolkit. It goes beyond policy and configuration reviews. It’s about actively testing systems, defenses, and even facilities to find weaknesses before an attacker does. In this episode, we explore the fundamentals of penetration testing, with a focus on physical penetration testing, the difference between offensive and defensive approaches, and how integrated testing can give organizations a full-spectrum understanding of their risk exposure.
Let’s start with physical penetration testing. This form of testing involves simulating real-world attempts to bypass physical security controls—like locks, cameras, barriers, or guard procedures—in order to gain unauthorized access to a building, server room, or secure area. The goal is to identify weaknesses in physical defenses that could be exploited by threat actors.
Physical penetration tests are not just about sneaking into buildings. They’re carefully planned and authorized exercises that test everything from badge verification and tailgating risks to keycard duplication and door bypass techniques. The testers often act like actual intruders, dressing like employees, carrying fake IDs, or posing as vendors, to see whether security personnel, front desk staff, or building systems can detect and stop them.
Let’s walk through a practical example. A bank hires a cybersecurity firm to conduct a full-scope penetration test. As part of the engagement, a team attempts a physical breach. One tester wears a delivery uniform and approaches the back entrance of a regional office during peak business hours. An employee holds the door open for them—tailgating them right past two locked doors and straight into a hallway near the server room. Once inside, the tester documents exposed Ethernet jacks, unsecured laptops, and unlocked file cabinets. No data is stolen, and nothing is touched—but the findings are powerful. The bank responds by improving physical access controls, adding signage, conducting awareness training, and rotating badge codes. This test revealed real risks—and helped fix them before someone with criminal intent could exploit the same pathway.
Another organization may test their own staff’s ability to question unauthorized visitors. One common method involves planting USB drives in parking lots or lobby areas to see whether employees will plug them into internal systems. These tactics test human behavior, not just physical locks. And while this kind of testing may feel uncomfortable, it’s one of the best ways to find the soft spots in real-world defenses.
Of course, physical penetration tests must always be authorized and carefully scoped. Rules of engagement must be defined, legal teams must be involved, and all activities must be fully documented. These tests require permission in writing and often involve coordination with law enforcement or building management to prevent confusion or accidental escalation.
Now let’s move to the distinction between offensive and defensive testing. These terms refer to the posture and objective of the test—whether you are actively trying to breach a system, or passively evaluating how it responds.
Offensive testing includes tactics like penetration testing, red teaming, and simulated attacks. These are proactive efforts meant to simulate real-world attackers. Offensive teams—often referred to as red teams—probe systems, networks, applications, and even personnel to find weaknesses, bypass controls, and achieve specific objectives like data exfiltration or privilege escalation.
The benefit of offensive testing is that it mimics the techniques, creativity, and persistence of real attackers. Offensive testing shows not just where weaknesses are, but how those weaknesses could be chained together into a full-scale breach.
Let’s say a red team gains access to an internal server through an unpatched vulnerability. From there, they escalate privileges, access user credentials, and eventually compromise the human resources database. That sequence shows how seemingly small issues can lead to serious outcomes.
Defensive testing, by contrast, is focused on identifying and responding to threats. It includes tactics like log analysis, incident detection, anomaly detection, and blue teaming exercises. The goal is not to break in—but to find out how well existing systems can detect, respond to, and recover from attacks.
Where offensive testing asks “can we get in,” defensive testing asks “would we know?” and “how fast could we stop it?”
Both forms of testing are essential. Together, they provide a full picture of an organization’s ability to prevent, detect, and respond to threats. Many mature organizations alternate or combine these strategies through purple teaming—where red and blue teams work together during simulations, sharing findings and learning in real time.
Let’s look at an example. A national retail chain runs a combined red and blue team exercise. The offensive team attempts to exfiltrate customer loyalty data using spear phishing and internal movement. The defensive team monitors logs, detects the anomaly, blocks the exfiltration, and launches a simulated incident response. The exercise ends with a full debrief. Both sides learn. Processes are improved. And the organization becomes stronger because it tested both offense and defense—not just one or the other.
Now let’s talk about integrated penetration testing. This refers to combining different types of testing—physical, technical, human, and procedural—into a single coordinated engagement. Rather than testing a firewall in isolation or social engineering alone, integrated testing combines multiple vectors to simulate how real-world attacks unfold across systems and departments.
Integrated testing may include everything from physical breach attempts and phishing campaigns to vulnerability scanning, network exploitation, and access control testing—all within a single operation. The goal is to test the organization's ability to handle layered threats that begin with one method and evolve into others.
Let’s consider a real-world case. A logistics company wants a full-scope security assessment. The integrated test begins with a phishing campaign targeting warehouse staff. When one employee clicks a link, the red team pivots into the network and finds an exposed file share containing outdated credentials. Using those credentials, they access a cloud dashboard with critical data. Meanwhile, a physical test team gains access to the server room by posing as HVAC technicians. Both paths converge when the testers simulate data exfiltration using a rogue wireless access point planted onsite. The final report maps each vector, identifies weak controls, and recommends improvements to security awareness, segmentation, and access monitoring.
Integrated penetration testing offers a realistic view of security risk. It helps leadership understand how different weaknesses combine—and where to focus limited resources for the biggest return. It also supports compliance in industries where defense-in-depth is required by regulation.
From a Security Plus exam perspective, be ready to distinguish between physical penetration testing, offensive versus defensive approaches, and integrated assessments. You may see questions that describe a simulated break-in, a phishing test, or a red-blue team exercise and ask what kind of testing is being performed.
Here’s a quick study tip. If the test involves unauthorized entry, badge testing, or USB drops, it’s physical penetration testing. If it involves attacking and breaking into systems, it’s offensive testing. If it involves monitoring, response, or detection, that’s defensive testing. If the scenario combines multiple methods in a single coordinated effort, it’s integrated penetration testing.
For downloadable rules of engagement templates, red team planning guides, and purple team playbooks, visit us at Bare Metal Cyber dot com. And if you want the most complete and exam-focused Security Plus guide available—complete with real-world examples and hundreds of practice questions—go to Cyber Author dot me and order your copy of Achieve CompTIA Security Plus S Y Zero Dash Seven Zero One Exam Success.
