Best Practices for Penetration Testing: Optimal Timing and Effective Techniques

Paul Hadjy

March 14, 2024

Best Practices for Penetration Testing: Optimal Timing and Effective Techniques

Threat actors are leaping over traditional barriers with ease, demanding sharper defenses for our widening attack surfaces. They are constantly on the move, probing IT infrastructure to identify vulnerable systems – including unpatched endpoints, network misconfigurations, unsecured APIs, and long-forgotten cloud permissions. Keeping up with network changes and closing these security gaps is a never-ending, manual endeavor that saps IT resources, time, and morale. The result: unnecessary security risk. After all, you can’t secure what you don’t know about. 

Penetration testing has emerged as a viable solution for detecting security risks and at enterprise scale – using automated detection technologies and manual investigation to root out and resolve network and system vulnerabilities. But not all penetration testing solutions are created equal. Organizations need to approach penetration testing carefully and ethically and with the right tools to ensure they can identify and resolve security gaps before threat actors have a chance to exploit these vulnerabilities. And, with anything in today’s constantly evolving threat landscape, timing is everything. 

What is Penetration Testing and How does it Work? 

Penetration testing is a security service that looks for vulnerabilities in enterprise systems and applications that are exploitable by an attacker, then provides recommendations to improve security posture. Depending on your organization's attack surface and potential risk profile, testing should be conducted regularly across the entire IT stack. This includes web applications, networks, web services, wireless access points, mobile applications, Internet of Things (IoT) devices, and thick clients, to ensure comprehensive security coverage. 

Penetration testing comes in different flavors — white, grey, and black box testing—each designed for specific security checks. Think of white box testing as giving the tester a VIP pass to your system. They get to see everything: source code, blueprints, passwords. This deep dive lets them spot every possible weak spot, making sure nothing gets missed. 

Grey box testing is like giving testers a sneak peek. They get some info, but not the whole picture, allowing them to think like an insider without full access. This way, they can uncover vulnerabilities that might not be obvious. Black box testing is all about surprises. Testers go blind, just like a real hacker would, challenging your defenses without any insider knowledge. 

Then there's red teaming, which takes things up a notch. It's like conducting a full-blown security drill, targeting your most valuable assets with sophisticated, realistic attacks. This approach checks not just for weak spots but also how ready your team is to handle real threats. With strict rules to keep things safe, red teaming pushes your security to the edge, giving you a clear picture of where you stand. 

For red team simulations different scenarios can be run in which security teams are in various stages of understanding the test's parameters. Teams can know that an attack is coming but not how the initial access will occur or be completely in the dark and must assume that a real breach attempt is in progress. Either way, someone inside the organization is in the loop and can mitigate any misunderstandings over the course of the test. 

How does Penetration Testing Fit within the Overall Cybersecurity Strategy? 

Penetration testing is a critical component of an organization’s overall cybersecurity strategy, designed to identify vulnerabilities and assess the effectiveness of security measures. On a practical level, penetration testing helps security teams keep up with application, network and systems changes so they can close any potential vulnerabilities or gaps that crop up. Today’s security teams must assume that expanding threat surfaces and cloud complexity mean that breaches will occur. A strategy that layers protection on top of detection is the best way to stop most attacks from occurring while mitigating any potential impact.  

When Should Penetration Testing be Conducted? 

Penetration testing should be conducted prior to the launch of new or meaningful change of existing assets, before auditing, to ensure compliance and as a regularly scheduled check. The important thing to remember is that your applications, networks, and systems are constantly changing – as does the threat landscape. What is secure today may not be secure tomorrow, making it important for organizations to conduct regular penetration testing across their entire IT stack. 

What is the Best Type of Penetration Test? 

White box testing is often the best choice for checking your system's security because it looks at everything in detail. It's like giving testers a full map of your system, so they can check every corner for issues. This is especially useful for things like website testing, where knowing all the various parts and user roles helps testers make sure nothing gets missed. With white box testing, they can spot problems that might let someone gain unauthorized access or control. 

On the other hand, grey and black box testing do not show the full picture. They try to see things from an outsider's point of view, which is good for understanding how an attacker might break in. But, because they do not have all the information, they might not catch everything. These methods are great for simulating attacks from someone who does not already know your system inside out, but they might miss the kind of issues that someone with more knowledge or stolen access could find.

Simply put, white box testing helps make sure we have checked everywhere and have not missed any potential security problems. It gives testers all the info they need to do a thorough job. 

Are There Scenarios When Penetration Testing Would be Inappropriate? 

The decision of whether or when to conduct a penetration test is not always straightforward. The critical factor is the impact on the business. It’s important to root out vulnerabilities and fix them in a timely manner, but testing needs to be done non-intrusively in a way that does not inhibit the organization’s ability to conduct normal operations. Avoid peak times, the middle of product launches, earnings announcements, and other critical events. It may seem like a promising idea to assess your security readiness when it matters the most, but disrupting operations and costing the organization revenue opportunities is never a good idea.
It's important to conduct penetration testing primarily in development and testing environments to avoid disrupting live systems. This approach ensures that daily operations, users, customers, and partners remain unaffected. But operational technology (OT) systems, where development environments might not exist, require special attention. Testing these systems demands a careful approach to prevent any disruptions, due to the significant impact that issues could cause. Ensuring due process, establishing clear rules of engagement, and securing authorization from relevant parties are essential steps in this context. 

Steps for a Successful Penetration Test 

Penetration testing is not something to undertake lightly. It requires meticulous planning and preparation to ensure it is conducted smoothly and yields useful results. The process begins with scoping. Collaborate with your penetration testing service provider to fully understand the systems, networks, or applications under review and their architectural framework. This step is crucial for determining the appropriate testing methods and establishing benchmarks for success. 

Next, decide on the type of penetration test—white, grey, or black box—that best fits your objectives, considering the insights from the scoping phase. It's essential to define the rules of engagement and set clear testing parameters upfront. Throughout the testing process, validate the findings to distinguish genuine vulnerabilities from false positives, ensuring the final analysis is both accurate and actionable. 

The culmination of this effort is a comprehensive report detailing all identified vulnerabilities and risks, coupled with actionable recommendations for remediation. After implementing the suggested fixes, request a follow-up report from the penetration testing service provider. This document should confirm the remediation efforts and outline the improved security posture post-remediation. 


Penetration testing is a critical component of a robust cybersecurity strategy that layers protection on top of detection. It allows cybersecurity teams to identify and resolve vulnerabilities to networks, applications and systems while staying on top of active security risks. However, organizations should approach penetration testing carefully and ethically and with the right tools to best identify and resolve security gaps before it’s too late. Regular testing built into business processes such as application development, provisioning cloud resources, and compliance auditing can mitigate security risk. Just make sure that you properly scope each test, outline the parameters and rules of engagement, and avoid disrupting business operations.

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Paul Hadjy

Paul Horangi is the CEO and co-founder of Horangi Cyber Security, a Bitdefender Company, a leading cybersecurity firm founded by ex Palantir Technologies engineers and is headquartered in Singapore. Horangi’s best-in-class Warden cloud security platform protects organizations in the public cloud, complemented by an elite team of cybersecurity experts providing CREST-accredited offensive and strategic cybersecurity services to customers across the world. Paul Hadjy manages the efforts behind creating cutting edge, cyber security solutions while ensuring that users in the C-suite down to technical operators are all armed with the right, actionable data to make critical cyber decisions.

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