Pen Testing Companies

When you hold up a newspaper or scroll through news channels every morning, there appears to be a new headline about the most recent cyber security incident. Hackers are stealing billions of dollars and millions of documents at a startling rate. Conducting comprehensive penetration tests throughout the year is crucial to countering their attempts. This is more than just a compliance decision; it’s about protecting your digital assets from ever more sophisticated cyber-attacks. One cannot stress how crucial it is to choose the best from the top pen testing companies. Always remember that taking shortcuts in the field of cyber security can have disastrous results. In this blog, we will look into the world of pen testing and its methodologies and highlight the top 12 pen testing companies in the UK for 2024.

What Is Penetration Testing?

A penetration test, sometimes referred to as a pen test, simulates a cyber attack on a computer system to look for weaknesses that could be exploited. Pen testing is the process of attempting to compromise any number of application systems to find weaknesses like unsensitised inputs that could be attacked by code injection. Finding weaknesses that an attacker can exploit is the primary objective of a pentest. Processes, methods, and services created and put into use with the intention of modelling attacks and data breaches and identifying security flaws are referred to as penetration testing or pen testing. A pen test can be performed on a web application, a network as a whole, or a computer system.

Penetration testing is also, at times, used to supplement a web application firewall in the context of web application security. A pen tester or a team of pen testers locates security flaws in the system, network, or application and assists you in resolving them before hackers discover them and take advantage of them. The penetration test’s insights can be utilised to improve your WAF security policies and fix vulnerabilities that are found. Now, depending on the project’s scope and the test’s intended goal, different penetration tests may be carried out differently. Here are several varieties of penetration testing methodologies:

  • Black Box Testing
  • White Box Testing
  • Gray Box Testing
  • Network Penetration Testing
  • Web Application Penetration Testing
  • Mobile Application Penetration Testing
  • Social Engineering Testing

Top 12 Penetration Testing Companies in the UK for 2024

Security experts can efficiently identify and test the security of online services, custom apps, multi-tier network architectures, and other IT components with pen testing. But how do you determine which service provider is best for you? There are some critical criteria for evaluating pen testing companies. For example, one must always look for companies with a proven track record and experienced pen testers. You should also ensure that the company offers a wide range of services that fit your requirements. It is always better to check for certifications, industry recognitions, etc., as these validate a company’s expertise. But you don’t have to remember any of it or do background research on cybersecurity companies because we have done it all for you. Here is a list of the top 12 cyber security companies in the UK.

1. Pentest Limited

Headquarters: Manchester, UK
Established Year: 2001

Pentest Limited is a well-known company with over two decades of experience in cyber security. It specialises in penetration testing services with a focus on web application testing, network testing, and social engineering assessments. In terms of industry recognition, Pentest Limited has several awards for its high-quality services and expertise in identifying and mitigating security risks. They also have a high customer satisfaction rate, making them worthy of the number one position in the top 12 penetration testing companies in the UK.

2. NCC Group

Headquarters: Manchester, UK
Established Year: 1999

NCC Group is one of the most renowned companies in cyber security. They have been the global leaders in risk mitigation, network penetration testing, and security consulting services. The company has received numerous certifications and honours for its continued effort to achieve cybersecurity excellence. NCC Group’s clients are testimony to their dedication and proactive approach to cybersecurity.

3. GoAllSecure

Headquarters: London, UK
Established Year: 2022

GoAllSecure is a relatively young but rapidly growing cybersecurity company with a focus on offensive security. They offer a broad range of services, including penetration testing, vulnerability assessments, red teaming exercises, and security consultancy services. This young company has immense potential, and that is why they have created a name for itself in the cybersecurity industry. According to GoAllSecure’s clients, their team has skilled professionals with various industry certifications. They have a distinct approach towards cyber security and an undying commitment to delivering quality services. They might be new to the market but have undoubtedly created a special place for themselves among the best pen testing companies in the UK.

4. Rapid7

Headquarters: London, UK
Established Year: 2000

Rapid7 is a top cyber security company offering its world-class services like penetration testing, vulnerability management, incident response, etc. They have established their name in the industry based on advanced technologies and holistic security solutions. They are a reputed name in the cyber security industry. They have received several accolades for their contribution to cyber security. Rapid7 is commended by its clients for its comprehensive reports and responsive support team.

5. NotSoSecure

Headquarters: London, UK
Established Year: 2007

NotSoSecure is a cyber security company that focuses on advanced penetration testing, red teaming, and security training services. They have a specialised team with heaps of expertise in identifying and mitigating complex security risks. In terms of their industry recognition, they are fairly popular and have garnered recognition in training workshops, cutting-edge research, and practical approaches to cybersecurity challenges. NotSoSecure has a loyal customer base due to its technical depth, valuable insights and customised solutions.

6. Nettitude

Headquarters: Leeds, UK
Established Year: 2003

Nettitude is a brand name in the cyber security industry that offers penetration testing, threat intelligence, and managed security services. It also offers security consultancy services and has a team of certified cybersecurity professionals who execute comprehensive security assessments and remediation strategies. Nettitude has received many industry accolades for its innovative solutions and commitment to delivering the best security outcomes. Clients commend it for its world-class services and proactive security recommendations.

7. SecureWorks

Headquarters: London, UK
Established Year: 1999

SecureWorks is a London-based cyber security company that provides pen testing, threat intelligence, and managed detection and response services. They are a big name in the UK cyber security community. They have been recognised for their advanced threat analysis technology and proactive threat detection and response capabilities. SecureWorks has a team of professionals from all around the globe. Their team is well-trained and the best in their field. Clients are always filled with praise for SecureWorks and their team’s dedication to keeping them safe.

8. F-Secure Consulting

Headquarters: London, UK
Established Year: 1988

F-Secure Consulting is among the group of companies that began the cyber security culture in the UK. They have been operating since 1988 and have been offering services like penetration testing, incident response, and security assessments. They have in their team some of the finest and most seasoned cybersecurity professionals who bring a vast amount of experience and technical expertise to the table. F-Secure Consulting has earned fame and accolades for its innovative cybersecurity solutions and for being a great leadership example for the industry. They have a long list of clients that have only the best things to say about their work. F-Secure Consulting’s dedication to security and commitment towards clients is commendable.

9. Cyberis

Headquarters: Tewkesbury, UK
Established Year: 2011

Cyberis is a reputable cyber security service provider specialising in customer-focused information security, threat intelligence, pen testing, and more. Its expert team provides its clients with personalised security solutions uniquely suited to them. This company is renowned for providing specialised security solutions for challenging cyber security issues. Cyberis’s numerous accolades attest to their proficiency and exacting standards in the field of cyber security. Clients speak exclusively well of Cyberis and its services. You can count on them to provide excellent technical support, comprehensive evaluations, and strategic security advice when you approach them.

10. PwC UK

Headquarters: London, UK
Established Year: 1849 (PwC UK’s cybersecurity division)

PwC UK is a household name; they have decades of experience in the field of cyber security. Their team specialises in penetration testing, red teaming, and security assessments. This award-winning team consists of certified ethical hackers and security professionals with extensive knowledge of identifying and mitigating security vulnerabilities. PwC UK has received accolades from industry peers and clients alike for their innovative contributions to cyber security. They have an extensive clientele due to their thoroughness, technical proficiency, and actionable recommendations. PwC UK has gained positive feedback from clients across various industries, making it one of the top pen testing companies in the UK.

11. Secarma

Headquarters: Manchester, UK
Established Year: 2001

Secarma specialises in penetration testing, red teaming, and cyber security consultancy services. The company bring valuable expertise and innovative approaches to penetration testing and cyber security, making them trusted choices for organisations seeking reliable security partners in the UK. Clients value Secarma for their professionalism and commitment to delivering value-added services.

12. MDSec Consulting

Headquarters: London, UK
Established Year: 2004

MDSec Consulting is a renowned cyber security firm with over 17 years of experience in penetration testing, red teaming, and security assessments. They have a very qualified and dedicated team of professionals working for them. MDSec Consulting has a glorified client list that trusts them to keep their businesses safe from malicious threat actors. This firm has received countless awards and accolades from the industry for its contribution to the field of cyber security. No one matches their professionalism and commitment when it comes to identifying and mitigating security vulnerabilities.

Penetration Testing Process: How is it Done?

Penetration testing is all about finding vulnerabilities. Now, these vulnerabilities can be discovered using a few different methods. You can choose between automated penetration testing carried out by a software program and manual pen tests carried out by a group of pen testers. The penetration testing procedure involves planning an attack, examining the target system for weaknesses, breaking through the security perimeter, and continuing to have access covertly. These are the first steps taken by penetration testers; let’s have a detailed look at them:

Information Collection and Reconnaissance

A penetration testing team must first obtain sufficient knowledge about the potential target before taking any further action. This time frame is essential for developing an offensive strategy and acts as a staging area for the whole process.


After the reconnaissance phase, the target is subjected to several scans to see how their security systems will fend off repeated breaches. Identifying vulnerabilities, open ports, and other weak points in the network infrastructure can determine the course of a planned attack by pen testers.

Getting Authorisation

Penetration testers use popular online application techniques like SQL Injection and Cross-Site Scripting to take advantage of any potential vulnerabilities after gathering data. Now that they have access, testers try to mimic the extent of possible harm that could result from a malicious attack.

Preserving Access

Attaining a state of constant presence within the target environment is the primary objective of this stage.

Analysing and Covering Tracks

Ultimately, to maintain anonymity, all attack traces must be removed after the engagement. Any executables, scripts, or log events that the target might find should be totally untraceable. The target will receive a detailed report that includes a thorough analysis of the entire interaction, including critical vulnerabilities, gaps, the possible consequences of a breach, and many other crucial security programme elements.

Importance of Penetration Testing in Cyber Security

Because penetration testing is one of the most significant ways to identify and address security flaws in a system before an attacker can take advantage of them, it is crucial, to say the least. Organisations can stop or reduce the harm that an attacker could cause if they successfully exploit a security flaw by carrying out penetration testing. Regular pen testing will verify your defensive measures to guard against prospective and actual attacks. It will inform you whether your security solutions are performing as planned. Pen-testing is essential for all businesses because it:

  • Determine and rank the security risks along with finding security holes so that they can be fixed.
  • Make sure your current security measures are working by use of a proactive defence strategy.
  • Find newly discovered flaws in current software and handle weaknesses with intelligence.
  • Encourage adherence to pertinent privacy and security rules and regulations by your organisation.
  • assist in adhering to regulations, including the Payment Card Industry Data Security
  • Standard, or PCI DSS.
  • Reassure clients and other stakeholders about the security of their data.

Selecting the best from these top penetration testing companies is essential to protecting your digital kingdom from outside invaders, not only to crossing an item off a compliance checklist. And believe us when we say that those savages aren’t pausing for a tea break. You can trust GoAllSecure for all your cyber security needs. Our penetration testing services, which have earned CREST accreditation, are designed to fit your budget, business needs, and the value you place on the assets you plan to test. If you have any queries regarding penetration testing, contact us at +91 85 2723 7851 or +44 20 3287 4253.