Top 5 Penetration Testing Methodologies

When it comes to protecting networks and infrastructure against cyber-attacks, penetration testing remains one of the most effective and efficient ways to analyze strength and posture. Specifically, this testing mimics attackers’ actions so you get a clearer idea of what’s at stake.

That said, there are a few different ways of running and managing penetration testing. In this guide, we explore the most effective penetration testing methodologies and how they differ.

What is Penetration Testing Methodology?

A penetration testing methodology refers to how pen testing procedures, or ethical hacking, takes place. It can refer to actions taken, tools used, and specific testing focuses. It’s a series of technical guidelines followed to ensure security vulnerabilities are found and investigated.

For example, some internal penetration test methodologies might focus on attacking internal APIs and servers, while others might focus on code injections through web applications.

Whether external or internal testing, the methodology you use will vary depending on your needs and the processes followed by your chosen tester. Consider researching options such as ISSAF, the Information System Security Assessment Framework, or any of those we explore below.

Top 5 Penetration Testing Methodologies

Penetration testing is never a one-template process – we’ve brought together the five most popular and effective methodologies used by experts worldwide. Let’s explore what each methodology covers, and why you might consider using them.

Open Source Security Testing Methodology Manual (OSSTMM)

The OSSTMM, developed by the Institute forSecurity and Open Methodologies, or ISECOM, remains one of the most popular methodologies for its broad acceptance among cybersecurity peers.

This penetration testing framework takes a straightforward, scientific approach to testing infrastructure vulnerabilities.Over the years, it’s expanded from an initial network focus to cover aspects such as IoT, cloud computing, wireless connectivity, and general ops.

Key elements of this methodology can include:

• Testing communication channels such as SMS, Bluetooth, email, and WiFi
• Analyzing physical operations, security policy standards, and potential for human error
• Assessing the potential for security maintenance and adherence
• Deep scientific measuring of general test metrics
• Researching potential areas of attacker ingress and egress (e.g., phishing, social engineering, firewall misconfigurations, source code weaknesses)

Open Web Application Security Project (OWASP)

The OWASP testing guide is a non-profit platform that aims to make web application penetration testing free and accessible to all who might need it.  

It’s well-known for its Top 10, which advises business owners and network operators of the biggest threats currently at large. As the name suggests, it’s specifically targeted at the external testing of web applications.

OWASP’s flexible pen test framework proves particularly useful for operators and businesses with custom APIs, IoT devices, and customer-facing mobile applications. It’s also relied upon to spot logical security issues – even in physical security – that might have been missed.

Key elements of this methodology can include:

• Simplified testing phases –gather, assess, analyze, review
• Specific code injection, security controls, and authentication analyses
• Detailed test typing and reporting(such as input validation and ID management)
• Flexible web app reconnaissance based on APIs and popular frameworks

National Institute of Standards and Technology (NIST)

The NIST methodology largely focuses on penetration testing developed to benefit government agencies and holders of highly sensitive information. Many consider the rules set by NIST to be the absolute minimum.

This methodology, otherwise known as NISTSpecial Publication 800-115, is highly specific and routine. It has clear but meticulous guidelines for companies of all sizes. It’s considered one of the most technical network penetration testing methodologies, though it’s designed to run broad and deep.

Key elements of this methodology can include:

• Meticulous planning stages and scoping, which includes establishing team responsibilities
• Scrutinous attack method planning and network movement mapping
• Deep reporting covering basic findings, potential diagnoses, and recommended remediation
• Discussion of ethical and legal considerations for penetration testing

Penetration Testing Execution Standard (PTES)

The PTES methodology was designed by penetration testers and cybersecurity professionals to provide a thorough oversight of network infrastructure vulnerabilities. Essentially, its purpose is to become the absolute “bottom line” of penetration testing on which all operators should follow.

This methodology provides careful technical guidance from the start to the end of any given penetration testing strategy.Many professionals rely on the PTES method to guide them through often complex procedures.

Key elements of this methodology can include:

• Exploitation and post-exploitation analysis
• Best practice suggestions for testing methods and attack vectors (e.g., cross-site scripting)
• Detailed pre-engagement rule setting and legal considerations
• In-depth threat modeling and attack vector brainstorming

Council of Registered Ethical Security Testers (CREST)

CREST refers to an accreditation that penetration testers can obtain to ensure they offer high-quality vulnerability analysis and threat mitigation strategies to clients. It’s a standard that started life in the UK but has since expanded overseas.

CREST’s non-profit approach aims to help people and organizations fine-tune their security standards without letting restrictive budgets or a lack of knowledge get in the way. CREST penetration testing is designed to adhere to regulations recommended by ISO 27001 and PCIDSS and can help companies comply with the GDPR. 

Key elements of this accreditation’s methodology include preparing testers for:

• Detailed scoping and planning
• Custom reconnaissance procedures
• Exploiting specific weaknesses with pre-agreed testing tools and resources
• Developing a penetration testing report and data protection recommendations

Why is it Vital to Follow Penetration Testing Methodologies?

Following pen testing methodologies ensures that this type of attack simulation is handled safely and within guidelines set by security professionals.

When arranging penetration testing services, you want complete assurance that the experts you work with have a clear framework in place and that there are no risks of harm dealt through attack simulations.

Methodologies like those used above can help testers and their clients adhere to safe guidelines that will enable them to spot potential vulnerabilities and find recommendations. Blindly testing and mimicking attacks on infrastructure can be extremely hazardous and is never recommended.

Following penetration methodology templates also ensures businesses and operators adhere to regulatory and compliance guidelines. For example, some methodologies are developed with the GDPR and ISO principles in mind. These are specifically developed to cover all legal bases – making it easier for no stone to remain unturned.

Working without a methodology can also be complex – some companies might not need the depth of more technical strategies depending on their audiences. Others might not hold the sensitive data commanded by government agencies.

Meanwhile, some methodologies – such as OWASP– focus on web applications, which isn’t relevant to all companies seeking pen testing.

Crucially, a cybersecurity expert or team that follows a penetration testing methodology has a clear template or framework to back up their decisions. What’s more, the clients they work with are reassured that there’s a clear plan in place.

Methodologies also help testers narrow down specific attack choices and ensure they can agree upon vital steps with their clients. It’s better to establish a testing process than to improvise it.

Stages of Penetration Testing Methodologies

As you’ve seen, the most popular penetration testing methodologies will vary in terms of scope, focus, and depth. However, most will follow the same basic template or skeleton. Here’s what to expect from the average penetration testing methodology, stage by stage:

• Scoping and planning: Before any testing takes place, testers will develop clear methodology plans about functionality. This can involve scoping out the organization they’re working with and learning about their infrastructure. At this stage, a tester might decide between white box and black box testing, for example.‍
• Building inventory: Once testers know about their client’s scope and needs, they will start to accrue automated tools, interfaces, and processes they can use to start investigating. This can involve diving into methodologies to find recommended attack vectors and testing standards for specific needs.‍
• Reconnaissance: At the recon stage, testers use tools and techniques they’ve agreed upon to start looking for vulnerabilities and weaknesses in their clients’ infrastructure. They will record these flaws and use their lists to start their attacks in later stages.‍
• Analysis: Some methodologies require testers to further explore vulnerabilities before they start launching attacks. It’sbetter to be sure than to be sorry – and with both manual testing and automated vulnerability scanning, testers can be reassured about the attack vectors they have in mind.
• ‍Attack launch: After thorough analysis is complete, testers will use their tools and techniques to assess the strength of a company’s security posture. They do this by focusing on vulnerabilities found, using different attack strategies, and recording insights.
• ‍Reporting: The final stage of most penetration testing methodologies is to report back to the client. A tester will have recorded where potential flaws might reside, how they exploited them, and what actions clients should take to harden their network security postures.

As mentioned, this is just a simple overview of what you might expect from different types of penetration testing and the methodologies testers follow.

Ultimately, penetration testing methodologies help cybersecurity experts and their clients stick to the same page – and ensure all recommendations made fall in line with compliance needs.

With VikingCloud, you can always expect a clear, concise vulnerability assessment and attack plan – with zero improvisation!