Cybersecurity Penetration Testing: What Is a Pen Test and Why Do You Need It?
What is penetration testing in cybersecurity?
In the case of network and data security, not knowing your systems’ weaknesses can be dangerous. Pen testing, a part of ethical hacking, is the process of finding any vulnerabilities in your infrastructure that you might not be aware of. In this exercise, cybersecurity professionals launch a simulated attack, which mimics those that cyber criminals might use, to identify areas where your cyber defense is lacking.
You might think your data and systems are perfectly protected. However, vulnerabilities aren’t always as obvious as an open database. Insecure system configurations, software problems, weak authentication and access policies, and even business logic flaws can be potential weaknesses to be exploited.
Pen testers use a series of automated and manual testing tools to find exploitable vulnerabilities within the scope of the test. After penetration testing, testers prioritize the issues based on the severity of the potential damage each can cause, often using the common vulnerability scoring system (CVSS). This tells you how urgently the issue needs to be remediated or mitigated.
Pen testing vs vulnerability assessments
A vulnerability scan is an automated process that uses tools to identify potential weaknesses across your networks, applications, and systems, either on a regular schedule or as needed. Think of it as the first layer of defense: “You might have a hole.”
A vulnerability assessment goes a step further, involving human analysis of the scan results to determine which vulnerabilities actually matter. It answers the question: “Here’s where the hole actually matters.”
A penetration test, or pentest, takes this even further by manually testing the environment and demonstrating real-world impact. Testers chain multiple vulnerabilities together, simulate potential attack paths, and show how threat actors could exploit them to gain access or disrupt your systems. In other words: “Here’s the hole, here’s precisely how big it is, and if someone went through it, they could make exactly this much damage.”
Because only human insight can understand business logic and context, our penetration tests are manual-first and business-aware.
Real-world benefits of penetration tests
It might seem like pen testing is something you do just to tick a security box. However, the process can be extremely beneficial for your overall security posture.
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It identifies any security issues in your cyber defense that you were not aware of, allowing you to fix them. Even if you are unable to resolve them, you’ll at least know they exist and can monitor them.
Since the testers are external to your organization, they can look at everything with a fresh pair of eyes. They will not have the preconceived notions that your team, who are probably too immersed in the environment, might have.
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It tells you how those issues can be exploited by bad actors. This knowledge helps you re-evaluate your workflows, processes, and defense strategy.
It might be that a vulnerability seems minor but could be taken advantage of to cause a major breach or disruption in operations. Alternatively, it might seem significant but pose little real threat.
Knowing how it can be used can help you prioritize your defense measures.
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Pen testing helps you support compliance by demonstrating due diligence in protecting any personal or sensitive data your business owns. Proactive identification and remediation of security weaknesses shows you are serious about data protection.
At the same time, penetration testing can also demonstrate how effective your existing controls are. In fact, certain standards even require regular pen testing as part of the compliance requirements.
Pen testing targets
Penetration tests can target different parts of an organization, from networks, applications, and cloud environments to physical infrastructure and even personnel, to evaluate how well each layer resists real-world attacks.
Application pen testing
These are tests that look for vulnerabilities in mobile, and web applications, websites, and APIs. Some of the commonly found weaknesses in these types of tests are malicious code injections, authentication failures, and misconfigurations.
Network security testing
Your company’s network allows your employees to access information from external and internal sources. This means it faces threats from both these directions. Network pen tests assess the security of this infrastructure.
When the focus is on outward-facing assets, such as routers, servers, and websites, it is called external testing. Internal penetration testing simulates what a malicious insider or compromised employee device could do.
Cloud pen testing
Cloud penetration testing is the practice of assessing the security of applications, services, and infrastructure that run in cloud environments. It combines traditional pentesting techniques with cloud-specific checks to identify how an attacker could gain access, move laterally, escalate privileges, or disrupt services in a cloud context. Cloud tests can target virtual machines, containers, serverless functions, storage buckets, APIs, IaC templates, identity and access management, cloud service configurations, and network controls.
Social engineering simulations (Personnel pen test)
You cannot discount the role of people in cybersecurity incidents. Personnel pen testing assesses how susceptible your employees are to social engineering attacks. Testers use techniques such as phishing, smishing, vishing, or whaling to assess whether they can get your team to give out sensitive information. They might even try to sneak into your office and steal information, depending on the scope of the test.
Pen testing types and approaches
Penetration tests can be performed in different ways, from black, gray, and white box testing to full red team simulations, depending on how much information is shared with testers and how closely the test should mimic a real attack.
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White box pen test
In a white box penetration test, the tester is given full or partial access to information about the target system, such as source code, architecture diagrams, credentials, and network details. Because the tester analyzes the original code and has deep visibility into the system, a white box test is often more time-consuming and therefore more costly. However, it provides a thorough understanding of potential vulnerabilities from the inside out.
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Black box pen testing
This type of penetration testing is performed by an ethical hacker with no prior knowledge of your systems, and the benefit lies in its realism: the tester approaches the target as an external attacker would, without any preconceived knowledge or assumptions. While a real-world attack might take longer due to limited information available to the attacker, a penetration test provides an assessment of the system based on the agreed scope and information provided, offering valuable insight into how an outsider could exploit potential weaknesses.
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Gray box pen testing
In a gray box penetration test, the tester is granted limited knowledge and access authorization. This may include employee-level credentials, partial system diagrams, or restricted network information. The goal is to simulate attacks that come from an insider or from a threat actor with some foothold, and to measure the likely scope of damage when credentials are stolen or an insider acts maliciously. Gray box testing offers a balance between realism and efficiency, combining targeted insight with the external perspective of an attacker.
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Red teaming
Red teaming is a realistic, covert attack simulation carried out without prior notification to the IT and security teams. Authorized by senior leadership, it replicates sophisticated, multi-stage adversary behavior across people, processes, and technology to evaluate detection, response, and recovery. Because of its potential impact, the engagement’s objectives, scope, permitted techniques, and rules of engagement are all agreed and signed off in advance to ensure legal and operational safety.This type of testing—often also called Red Teaming—is carried out without the knowledge of the IT and security teams who would defend against an attack. It is signed off by upper management. Often, pen testers may be required to get the scope and techniques pre-approved by the authorizing party to avoid legal trouble.
The penetration testing process
Pen testers may uncover a range of vulnerabilities, but they almost always follow a short, repeatable process:
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Scoping and reconnaissance
Every engagement starts with planning, where the tester and client agree on goals, scope, and rules of engagement. They determine what systems are in bounds and what’s off-limits. Legal sign-off and emergency contacts are confirmed before anything begins.
Once that’s in place, testers start gathering information about the target—public data such as domains, IP ranges, and services, as well as any internal details the scope allows. This stage sets the foundation for modeling threats and planning attacks.
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Scanning and analysis
Using what they’ve learned, testers look for potential weak points. Automated scanners identify known vulnerabilities, which the pen testers review manually to remove false positives and gauge real risk.
They prioritize findings by how likely they are to be exploited and what damage they could cause. Only verified, high-impact issues move to active testing.
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Testing and exploitation
Here, the theory meets practice. Testers attempt to exploit validated vulnerabilities within the approved boundaries without causing disruption.
They might use methods such as SQL injection, brute-force attacks, or privilege escalation to show how an attacker might gain access, escalate privileges, or move through the network. Each successful exploit shows how multiple weaknesses could be chained together for greater damage
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Cleanup and evidence preservation
Once they gain access, the testers assess how long an attacker could maintain it. Part of this step is to take care that their own testing leaves no lasting changes or backdoors.
When testing concludes, they remove any temporary accounts, scripts, or files created during the engagement.
They securely preserve logs and evidence to support the final report and any compliance needs.
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Reporting and remediation
The final stage turns findings into action. Testers compile two types of reports: an executive summary and an operative report.
The executive report is designed for high-level stakeholders. It highlights the number and severity of discovered issues, their potential business impact, and recommended next steps.
The operative report is highly technical and intended for the security and engineering teams. It includes detailed evidence, CVSS scores, and clear remediation steps for each finding.
Once critical issues are resolved, testers perform a retest to verify the effectiveness of the fixes. The results inform future security improvements and help teams strengthen detection and response over time.
Learn more about our penetration testing process here.
TOOLS WE USE
Penetration testing tools
Pen testing teams complement manual tools with automated ones to identify, exploit, and report weaknesses in the systems. While these tools don’t replace the human judgment needed to interpret results and chain vulnerabilities together, they do speed up repetitive tasks and help validate findings.
Here are some of the tools ethical hackers use to find vulnerabilities in your systems:
Reconnaissance and vulnerability scanning tools
These tools go through the target environment to map out potential attack surfaces. Examples include Nmap, which identifies active hosts and open ports, and Nessus, which scans systems for known vulnerabilities.
Web app & API testing tools
Used to find weaknesses in web applications and APIs, such as cross-site scripting (XSS) or SQL injection flaws. Tools like Burp Suite Professional, SQLMap, Nuclei, testssl.sh, Feroxbuster, and Gobusterr help testers design traps to intercept traffic and manipulate requests, and the responses are analyzed to check for behavior that affects security.
Network exploitation frameworks
Frameworks like Metasploit allow ethical hackers to launch controlled exploits against target systems. Tools like Nmap, NetExec, BloodHound, Certipy, smbclient-ng, Impacket-collecton or Repsponder help our professionals test how far a vulnerability can be leveraged and simulate real attack chains safely within the defined scope.
Password and credential testing tools
Applications such as Hydra or John the Ripper are used to test password strength and uncover weak authentication mechanisms. These tools reveal how easily an attacker could gain unauthorized access.
Wireless and IoT testing tools
Specialized tools like Aircrack-ng, Kismet, tcpdump or Wireshark help testers analyze wireless traffic. They are also useful for detecting insecure configurations and capturing packets. For IoT or embedded devices, testers often use firmware analysis utilities or hardware debugging tools to assess exposure.
Reporting and documentation tools
For reporting, we primarily use good old Google Docs or Microsoft Word, alongside the CVSS calculator to ensure consistent risk assessment. Notes, logs, and files collected during the penetration test are carefully reviewed, organized, and manually compiled into a comprehensive final report.
Penetration testing best practices
No matter how effective a tool or service might be, you need to follow certain guidelines to get the most value out of it. Here are some best practices for pen testing:
Define clear objectives
You need to have a clear idea of what you want from the test. Is the purpose to verify that you are compliant, or is it to make sure your controls work? Maybe you would like a real-world attack simulation. Whatever your objective, defining it clearly will help the testers determine the scope and methods they should use.
Set precise scope and rules of engagement
Be very specific about what environments you want to test. Have clear boundaries, and get approval on paper before you continue. This will help prevent unexpected business disruptions.
Communicate with internal teams
Even if it is a covert test, there will be an internal department that would need to know about it, even if it is the legal team. Tell them when the test will occur and how incidents will be handled.
Provide realistic access and data
If you are sharing credentials or architectural details for white- or gray-box testing, make sure that they are accurate and relevant. If not, the testers might end up focusing on false positives rather than genuine risks.
Act on the results
The testing and results should not be treated as an intellectual exercise. Implement the remediations, but do so based on the severity scores. Assign roles and responsibilities along with deadlines, and track the fixes till completion.
Retest to verify fixes
It is important to retest after you have made the fixes, not just to ensure that they work, but also to check if they have created any new vulnerabilities.
Invest in regular testing
Pen testing should not be a one-and-done exercise. Threats evolve as new technologies emerge, and new vulnerabilities can arise over time. Regular testing will keep you compliant and secure, now and into the future.
Would you like to use our cybersecurity penetration testing services to keep your business secure?