Penetration testing, or pen testing for short, is a critical way to protect IT systems and sensitive data from malicious activity proactively. This guide provides a comprehensive overview of how this technique works, business benefits, its types, methodologies, costs, and everything in between.
Penetration testing, commonly known as pen testing, is a simulated cyber attack exercise to find exploitable security flaws in IT systems and services. This method involves an ethical hacker simulating malicious behaviour and activities to gain insights into possible areas of concern and reinforce safety and security measures.
For penetration tests to be successful, they require a strong knowledge of the analytical ability and a technical understanding of the target (a system, service, or web application). Penetration testers allow organisations to access their blind spots, i.e., assess and mitigate weaknesses to reduce the attack surface. Penetration testers utilise testing tools to effectively simulate attacks and identify vulnerabilities, enhancing their ability to secure systems against potential threats.
Penetration testing aims to ensure the security of your systems, applications, and services. An external third-party penetration testing services provider conducts this exercise that provides an accurate representation of the security posture of a target system, network, application or service. Pentesting results also help to improve internal processes for vulnerability assessment and management. Although it is used to identify vulnerabilities, it’s not a primary source of finding vulnerabilities.
The exact tools and techniques used by penetration testers vary based on the scope and target of the pentest engagement.
Penetration testing provides multiple business outcomes that improve the risk management capabilities of an organisation from reactive to proactive. All organisations should be aware of the stealthy ways in which threat actors can target their organisations or supply chains.
A pen test supports a business at various stages of an asset. It could be before or during design, during a merger and acquisition, before a go live, during digital transformation, compliance, and so many other reasons.
Today, using cloud, SaaS, mobile devices, and remote working facilities mandates pen testing to ensure data protection.
This includes financial institutions (Banks, Credit unions), healthcare providers, and any company storing personal information (e.g., Social Security Numbers).
Many regulations (like PCI DSS for credit cards and healthcare) mandate penetration testing.
Websites, e-commerce platforms, and online stores and services are prime targets for attack.
While less common, attackers target small businesses due to the perception of weaker defences.
Penetration testing can be classified into various types based on the target environment and the specific security aspects they assess. Here’s a rundown of the ten most common types of pen tests across the UK and USA:
Internal network pen testing evaluates the security of an organisation’s network. Pentesters identify vulnerabilities that could be exploited by someone with inside access that could lead to privileged access to compromise a few systems to the entire network.
External network pen testing, on the other hand, simulates attacks from outside the organic organisation the Internet) to identify weaknesses that external threats could exploit.
⚡Example: An internal test might involve attempting to escalate privileges from a standard user account in an organisation, which is an insider attack scenario. In contrast, an external test assesses the attack surface of the network’s perimeter by identifying vulnerabilities in the exposed services.
The following image shows our network pen test approach in a flowchart style:
Wireless pen testing focuses on identifying security weaknesses within an organisation’s network. These weaknesses could relate to wireless network design, authentication, and protocols. This includes examining encryption weaknesses, authentication bypasses, rogue access point detection, logging, and monitoring.
⚡Example: Testing the strength of WPA2 encryption on a corporate Wi-Fi network to ensure it cannot be easily cracked.
Web application penetration testing evaluates web applications’ security and associated APIs. It assesses the targets against OWASP top 10 and other vulnerabilities, including but not limited to SQL injection, cross-site scripting, and insecure API endpoints that could be exploited.
⚡Example: Attempting to access unauthorised through an API by manipulating input parameters.
Mobile app pen testing assesses applications on iOS, Android, and other mobile platforms for security issues, including insecure data storage, weak server-side controls, device controls, and insufficient transport layer protection.
⚡Example: Testing an Android app to see if sensitive information is stored insecurely on the device.
Cloud pen testing assesses cloud-based services and infrastructure, such as AWS, Azure, or Google Cloud. It involves evaluating the configuration and security controls the cloud service provider provides.
⚡Example: Assessing an AWS S3 bucket for misconfigurations that could lead to unauthorised exposure.
This involves examining target systems and applications for secure configuration and deployment practices. It includes reviewing the settings of operating systems, applications, and network devices.
⚡Example: Reviewing a server’s configuration to ensure it is hardened against attacks.
IoT pen testing targets the Internet of Things (IoT) devices and their ecosystems, looking for vulnerabilities in the devices themselves and how they communicate with other systems.
⚡Example: Attempting to compromise smart connectivity linked services, networks, or a device to gain access to restricted networks.
SaaS pen testing focuses on software-as-a-service applications. Testers evaluate the application’s security in a multi-tenant environment and its security features for subscribers and identify potential data leaks between users or tenants.
⚡Example: Testing a SaaS or cloud platform for cross-tenant data access or privilege escalation vulnerabilities.
Red teaming assessment involves a full-scale simulation of an attack on an organisation’s safety posture. It combines setting up an attack to carry out a real-time attack on the organisation without more comprehensive staff or organisation employees being aware of the test. This is approved by senior stakeholders and is meant to check the organisations’ defences and whether people, processes, and technical controls are prepared to handle a cyber-attack. It assesses how well an organisation detects and responds to an actual attack.
⚡Example: A coordinated attack campaign that includes phishing, physical breach attempts, and network exploitation to test the organisation’s capabilities.
Social engineering pen testing assesses the human element of security by attempting to manipulate individuals into compromising their own or their organisation’s security. This can include tactics such as phishing, pretexting, baiting, and tailgating.
⚡Example: Sending a spoofed email that appears to be from the company’s IT department to employees, asking them to change their password by clicking on a malicious link.
The amount of information given to penetration testers is a crucial step that dictates the testing scenarios based on what is agreed with the customer. For instance, a web application source code review follows a white box approach where all information is shared beforehand. An API pen test follows grey box pen testing methods where user-level privileges are provided.
Organisations employ various penetration testing approaches that come with their own sets of advantages and disadvantages. White box, black box, and grey box are the three options to choose from regarding knowledge level about the computer system: white has complete information, black is conducted without any prior understanding, while grey combines both methods.
Selecting one that fits the organisation’s requirements will guarantee a successful penetration test services return on investment.
White box pen testing is a thorough method of evaluating the security standing of an application or system. Pen testers are given full access and information about the examined item, enabling them to simulate an attack using multiple strategies. This extensive analysis can give organisations an initial understanding of their security posture. It takes more time and resources than other testing approaches.
⚡An example of a white box pen test is a source code review and web application pentest together where the organisation intends to cover all weaknesses possible to secure the code.
Penetration testing with a black box approach gives an impression of a system’s security in its current state without any prior knowledge to the penetration tester. This strategy includes behavioural and functional testing that imitates an external attacker to discover weaknesses other pen tests could skip.
Despite being less precise than alternate techniques, this method is valuable for helping organisations find any potential gaps in their defence systems that might have otherwise gone unseen.
⚡An example of a black box pen test is a web application pen test for an online shopping website to mimic an Internet-based attacker.
Grey box pen testing is an approach that blends aspects of both white and black box approaches. The pen tester can access only some information regarding the evaluated system, thus providing a more practical evaluation than either one-sided technique alone. This permits a focus on particular components that could be exposed to weaknesses.
⚡An example of a grey box pen test is carrying out an internal infrastructure pentest assessment where different test cases are defined with network-only access, standard domain account access, etc.
Penetration testing methodologies are frameworks that guide ethical hackers through testing for vulnerabilities. These methodologies provide structured approaches to identify, exploit, and document security flaws. Here’s how organisations utilise some of the top methodologies:
The Open Web Application Security Project (OWASP) is an open-source application security project that organisations around the globe use to improve the security of their software. This mainly includes:
The OWASP methodologies include the famous OWASP Top 10, a list of the ten most critical security risks organisations should be aware of. Various top 10 risk lists from OWASP include:
The National Institute of Standards and Technology (NIST) Special Publication 800-115 provides technical security testing and assessment guidelines. It outlines approaches for planning, conducting, and analysing, including vulnerability scanning and penetration testing. Organisations use this methodology to align their security testing with industry standards, ensuring a comprehensive evaluation of their information systems and networks.
MITRE ATT&CK is a globally accessible knowledge base of adversary tactics and techniques based on real-world observations. It is a foundation for developing specific threat models and methodologies in the cybersecurity community. The ATT&CK framework is used to understand potential attack vectors, simulate adversarial behaviour, and enhance their detection and response capabilities with adversaries’ TTPs knowledge. By doing so, they can better prepare for and defend against complex cyber threats.
The Open Source Security Testing Methodology Manual (OSSTMM) provides a scientific methodology for accurately characterising operational security. It includes tests for various security controls, including physical, wireless, and telecommunications. By applying OSSTMM, organisations use a thorough and repeatable pen testing process that can be tailored to their specific needs, resulting in improved operational security.
The Penetration Testing Execution Standard (PTES) is designed to provide businesses and security service providers with a common language and scope for performing penetration testing. PTES covers everything from pre-engagement interactions to the final reporting, providing a complete roadmap for conducting successful penetration tests. Organisations use PTES to ensure a comprehensive and consistent testing process.
The Information System Security Assessment Framework (ISSAF) offers a structured approach to information systems security assessment. It covers a range of areas, including policy review, physical security, and technical testing. Organisations use ISSAF to assess their security posture holistically, allowing them to identify and mitigate various informational security risks.
Cyphere follows the following process consisting of six stages of penetration testing:
The first penetration testing phase is the initial scope and objectives agreement phase. In this phase, the security testing team and the client establish the testing goals, scope, and timelines. The testing team and client work together to complete the objectives agreement document, which outlines all the testing activities and explains what the client wants to achieve from the testing.
Surveillance is the second phase of the penetration testing process. In this phase, the security team gathers as much information about the target system as possible through passive and active methods. Passive methods include gathering information through social media, domain registration information retrieval, newsletters, press releases, etc. In contrast, active methods are done through various technical means, such as scanning the network and identifying publicly available vulnerabilities and patch levels.
Social engineering attacks are often out of scope unless explicitly agreed upon during scoping calls. Remote social engineering or electronic social engineering methods are frequently used during red teaming style exercises or specifically carried out to assess physical security controls assessment.
Now, the team uses the intelligence gathered during the reconnaissance phase to scan actively and to identify vulnerabilities, weaknesses, or configuration issues. During the vulnerability identification phase, the team tries to capture more data, such as server banners, open ports, and poor practices, which can be used to access the client’s IT network during the exploitation phase.
Exploitable vulnerabilities are assessed, and a layout is prepared to evaluate potential routes toward the most prized assets within the scope.
In this phase, the team leverages the findings from the vulnerability analysis phase to launch an attack on the target systems or network. This test imitates real-world attacks (a simulated attack). It attempts to access the client’s systems through various means, such as exploiting unpatched security flaws in applications, password guessing, safe exploitation of patching flaws, and maintaining access. Post-exploitation methods include remote access into the most secure areas and pivoting into various segments otherwise segregated from corporate or production networks.
Once the security team has completed the exploitation phase, they will report their findings, explaining how they managed to exploit known vulnerabilities in the system, what data they obtained, and how much damage they caused. At the end of this phase, a comprehensive penetration testing report is generated and given to the client, outlining all the vulnerabilities and the recommended actions to mitigate them.
This phase includes working with clients to support their risk remediation process and practically lead the risk reduction mantra. Cyphere is uniquely positioned to assist through our risk remediation support on the back of our work. This is often the moderate/mid-size organisation because once the pen test is delivered, it has the skill set required to guide it through the risk remediation process. Once remediation is complete, a retest is initiated to check the systems and web applications to validate the applied fixes.
Pentesting is critical to upholding industry regulations and risk assessment practices. Organisations go through regular penetration tests based on standards such as the OWASP Top 10, SANS 25, PCI DSS, NHS DSPT, NHS DTAC, Cyber Essentials, and other industry-specific requirements to detect security flaws and take measures to resolve those issues. This shows that an organisation takes active steps towards preserving its secure environment and safeguarding confidential data from unauthorised access.
Organisations better protect their systems and web applications from security risks by utilising widely accepted OWASP Top 10 and SANS Top 25 critical security controls. Incorporating these security features into pen testing strategies will allow them to pinpoint potential threats or vulnerabilities, increasing their overall safety posture. By staying up-to-date with industry standards such as these, organisations ensure that they effectively assess the most crucial dangers.
Organisations must ensure a comprehensive penetration testing program to adhere to the Payment Card Industry Data Security Standard (PCI DSS). Such internal and external security tests will help detect any security risks associated with their network infrastructure or web applications so that vulnerabilities can be identified and resolved, thereby complying with PCI requirements.
By showing dedication towards protecting cardholder data from potential security threats through compliance with these rules, organisations commit to safeguarding sensitive information.
ISO 27001 is an international standard for managing information security. It requires organisational risk assessment and the implementation of appropriate security controls, including regular penetration testing. Through penetration testing, organisations demonstrate that they have identified potential security vulnerabilities and taken steps to mitigate them, which is essential for ISO 27001 certification.
Under UK GDPR, organisations protect personal data against unauthorised, unlawful processing and accidental loss, destruction, or damage. Penetration testing is critical in identifying and addressing security vulnerabilities such as information storage weaknesses, encryption misconfiguration, and access controls around sensitive data and PII.
In the NHS and healthcare sector, the Data Security and Protection Toolkit (DSPT) and the Digital Technology Assessment Criteria (DTAC) set out requirements for managing data security. Penetration testing is vital for uncovering weaknesses that could compromise patient data and supporting healthcare organisations in setting their obligations to protect sensitive health information.
The Digital Operational Resilience Act (DORA) focuses on the ICT risk management framework within the financial sector of the EU. Penetration testing is essential for financial institutions to assess their resilience against cyber-attacks, ensuring they can promptly detect, respond to, and recover from operational disruptions. Threat-led penetration testing is mandatory for a three-year duration to ensure contextual risks are identified.
Penetration testing tools are integral to pentest assessments, providing the technical leverage necessary to uncover and address vulnerabilities. The right pen testing tools in the hands of skilled pen-testers can simulate various attack scenarios, revealing critical insights into system weaknesses. These tools are not the same tools for each test but range from open source to commercial solutions, each offering distinct advantages for security assessments.
Open-source tools are a cornerstone of the penetration testing community. They offer transparency, allowing users to inspect and modify the code to suit specific testing needs.
Tools like Kali Linux, which has hundreds of utilities and open-source tools, NMap for port scanning and vulnerability analysis, Wireshark for network analysis, and Metasploit for vulnerability exploitation, are widely respected for their capabilities and contributions to security research. However, they may require more technical expertise to use effectively and come with less formal support.
Commercial or paid penetration testing tools provide a more user-friendly experience with dedicated support and regular updates. These tools, which include advanced vulnerability scanners and network assessment software, are designed for efficiency and ease of use, catering to a broader range of technical abilities. While they come at a cost, the investment is often justified by the time savings and the comprehensive features they offer for rigorous security assessments. Examples include Metasploit paid version, Cobalt strike, Tenable, and other software.
Safe Exploitation in Penetration Testing
When procuring penetration testing services, discussing ethics and methodologies with the suppliers is essential to assess their approach. Reliable and safe use of exploits to understand what attackers might be able to do helps organisations understand the extent of weaknesses. Safe exploitation and agreeing objectives through formal and informal customer communications during the engagement decrease any chances for potential disruptions.
It is essential to understand the differences between automated and manual penetration testing. There are several differences between the two, as well as pricing gaps.
Automated penetration testing stands out for its speed and efficiency, specifically swiftly scanning computer systems to pinpoint known vulnerabilities. These tools can quickly detect common issues, such as misconfigurations, outdated operating systems, and application flaws. For example, an automated scanner might uncover vulnerabilities like an unpatched security vulnerability on a server or a misconfiguration flaw in a web application. Computerised tools have drawbacks despite their efficiency, often producing high false positives that require manual verification to confirm their relevance and accuracy. These tools are usually cheaper than manual penetration testing consultancy fees for pen testing projects.
Manual penetration testing harnesses the expertise of seasoned security professionals such as CREST-accredited penetration testers who meticulously emulate the strategies of attackers. These pen testers utilise a spectrum of techniques, ranging from social engineering to privilege escalation and even the discovery and exploitation of zero-day vulnerabilities—those security flaws unknown to the software vendor until they are exploited. Often, vulnerabilities such as business logic flaws go unnoticed with automated tools.
For instance, a manual pen tester may uncover a misconfigured firewall that inadvertently grants unauthorised access to a sensitive internal network, a subtlety that automated tools could easily overlook. Manual pen testing comes at a project-based price instead of a software licensing-based cost associated with automated pentesting.
With that said, organisations utilise both types of testing based on their requirements. A strategic blend of automated and manual testing is often the most effective approach for optimal security, regularly ensuring a robust and comprehensive assessment of an organisation’s security defences.
At least once a year or upon significant changes such as upgrades or changes that affect the system state, penetration tests are required. An organisation’s size, industry and risk appetite determine the need for penetration tests.
There are several other scenarios based on the size of the business and its cyber security maturity. For example, a few of them include:
Once annually is an excellent baseline to identify vulnerabilities and ensure security measures are effective. For a detailed answer, it depends upon the several factors that are included below:
A penetration test report results from a security assessment that identifies weaknesses in your systems. At Cyphere, we believe a report reader should be able to understand the risks, reproduce findings and understand risk remediation measures easily.
The report helps businesses improve their security posture and provides evidence for compliance or security practices.
All penetration testing reports from Cyphere include the following features:
We capture and agree on all objectives and drivers during pre-assessment discussions with customer point of contacts. This gives us sufficient time to tailor our delivery cycle around customer needs.
Penetration testing plays a vital role in cybersecurity for various sectors, offering benefits and adhering to specific mandates. Here’s a breakdown across critical sectors where Cyphere has strong expertise in delivering assessments with contextual knowledge:
SaaS businesses manage customer data and applications. Penetration testing helps identify vulnerabilities before attackers exploit them, protecting customer trust and data integrity.
Regulations like GDPR emphasise protection. Penetration testing demonstrates proactive security measures, potentially reducing the impact of data breaches.
Financial institutions handle sensitive financial data. Penetration testing uncovers weaknesses in systems processing payments, storing financial records, and protecting against fraud.
The Payment Card Industry Data Security Standard (PCI DSS) mandates regular security pentesting for organisations cardholder data. Compliance expects adherence to robust security protocols.
Healthcare organisations have sensitive patient data and medical records, including connectivity across OT and IT estates. Penetration testing safeguards these systems from breaches that could compromise patient privacy and disrupt critical healthcare services.
The Department of Health and Social Care (DHSC) requires NHS trusts to perform penetration testing as part of the DHSPT compliance framework. HealthTech companies must adhere to relevant Data Protection Act (DPA) and NHS guidelines, often requiring penetration testing and privacy as part of compliance with Digital Technology Assessment Criteria (DTAC). For interfacing such as NHS IM1, pentesting is also a mandatory requirement.
E-commerce businesses process customer payments and credit card information. Penetration testing identifies vulnerabilities in online stores and payment gateways, preventing financial loss and reputational damage from data breaches. This is checked against web applications, APIs and mobile applications.
While not explicitly mandated, complying with PCI DSS for storing cardholder data and adhering to GDPR best practices often involves regular penetration testing.
Schools are required to adhere to the Department of Education’s cybersecurity review guidelines and data protection responsibilities as organisations. Higher education institutes and universities manage student data, research information, and critical IT infrastructure/labs sensitive to the organisations and ho. Theyntellectual property (IP), national importance research data and valuable information for nation-state actors.
Universities specifically leading work in research or working with Defense, regulated sectors or governments require Cyber Essentials Plus and annual penetration testing. Apart from this, there are no overarching mandates. Still, the government’s National Cyber Security Strategy encourages educational institutions to adopt a risk-based approach to cybersecurity, which may include penetration testing.
EdTech companies handle student data, learning materials, and online platforms. Penetration testing safeguards these systems from unauthorised access, data breaches, and potential disruption to educational services.
Similar to higher education, EdTech companies are not explicitly mandated but may require penetration testing for contractual purposes or compliance with GDPR, depending on the data they handle.
Housing associations and social care providers manage sensitive personal data and have interconnected IT systems across cloud and software vendors for tenancy support. Penetration testing strengthens their cybersecurity posture, protecting resident information and ensuring service continuity.
When planning for penetration testing, the cost can depend on several elements, such as the project scope, company size, and city. A quality penetration test using a CREST penetration testing provider usually spans the £5000-£10,000 for a medium sized assessment and £10-20,000 for extensive evaluations. Companies can plan their budgeting better by knowing what affects price when it comes to such tests.
Specific organisations limit the cost factors by integrating multi-year contracts or frameworks (block booking) in their plans. On the other hand, vulnerability assessments cost is often a fraction of pen testing costs, therefore, it’s worth checking the differences between the two.
There are multiple businesses providing penetration testing services. These include specialist boutique service providers like Cyphere, IT, and MSSPs. Some of these providers include:
Before selecting a CREST-accredited company, clearly define your security needs and the approach that best aligns with them. The right penetration testing provider will act as an extension of your team, offering proactive support to ensure informed business decisions.
Before you partner, ensure you can count on them. Consider these factors when procuring a security partner:
Service delivery approach: A provider’s approach encompasses how they operate throughout the assessment process. This includes client intake, business context understanding, communication, execution, and post-assessment support.
Communication: Open communication is essential for a successful assessment. Choose a provider with a clearly defined communication plan, including formal and informal channels.
Consulting expertise: Prioritise sector-specific experience and knowledge of your tech stack over certifications or big brands alone. This experience enables consultants to benchmark your security posture against your peers, provide contextual pain points and food for thought and deliver tailored insights, ensuring the best value for your company.
Once, procurement decision has been made. It is time to ensure project management considers key factors when planning penetration testing schedules before informing other parts of the business. These factors include:
Choosing the right penetration testing provider is crucial for ensuring the security maturity of any business. By choosing the right provider, businesses can be confident that their valuable data is in good hands.
The primary purpose of pen testing is to simulate a cyberattack and identify vulnerabilities in the systems before attackers exploit them.
No, but it demonstrates proactive measures to secure data. GDPR focuses on data protection processes, not just technical controls.
Yes. Penetration testing is an authorised form of hacking that uses similar attack methods identical to those used abilities.
No, but it recommends regular vulnerability assessments and penetration testing as part of a strong security posture.
Absolutely. It’s conducted with client permission to identify and address security risks.
Business needs and goals for the test.
Scope and limitations of the penetration test.
CREST-accredited company and consultant qualifications such as OSCP, CREST, and CISSP.
Reporting format and post-test recommendations.
Penetration testing builds upon a vulnerability assessment. Vulnerability assessment includes scanning systems for known weaknesses, and penetration testing goes further by safely exploiting vulnerabilities to assess their impact and difficulty in breach.
SOC 2 doesn’t explicitly require it but emphasises penetration testing. Penetration testing can be valuable to meet these requirements.
Pentesting identifies vulnerabilities that could put you in breach of regulations, helping you know your blind spots and allowing for proactive fixes. It demonstrates your dedication to data security for auditors. It fulfils the testing mandates of specific regulations like PCI DSS or industry-specific regulations such as DORA, FCA mandate, and Commission Audits.
Penetration testing uncovers security flaws before attackers exploit them, helping you address weaknesses proactively. It goes beyond standard security scans to uncover hidden vulnerabilities and puts your defences through a real-world stress test.
Penetration testing helps you prioritise critical security vulnerabilities and associated remediations for maximum impact. It provides evidence to buy-in support for improvements, increase security budget and build employee awareness of cyber threats, leading to a more robust security culture.
✍️ What is Physical penetration testing?