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CREST Certified Penetration Testing Services

We find security weaknesses before attackers do

At Stripe OLT our CREST certified penetration testing team simulate real world attacks to find vulnerabilities across your organisation’s infrastructure, applications, cloud environments and more.

Every assessment is tailored to your business and industry needs - helping you reduce risk, meet compliance requirements, and strengthen your overall cyber resilience with actionable insights and expert guidance.

Need to test your security? Fill the form to speak to our pen testing team.

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Our Clients

Why Choose Stripe OLT for Penetration Testing

Over 20 years of cyber security and IT expertise underpin our penetration testing services. Discover why organisations trust Stripe OLT as their penetration testing partner.

CREST Certified

Our ethical hackers are CREST accredited, which means our experts have received an industry-leading certification and continuously deliver to the highest levels of pen testing standards.

Tailored Testing Engagements

Our penetration testing engagements are tailored to your organisation’s environment and objectives, ensuring you receive expert CREST-certified testing aligned to your specific risk profile and security requirements.

Comprehensive Reporting

You’ll receive a comprehensive report with in-depth remediation advice and guidance, presented in a language you can understand, helping your team clearly identify vulnerabilities and prioritise the actions needed to strengthen security.

benefits of offensive security testing

Identify exploitable security weaknesses before attackers do

Understand where your most critical security risks lie

Strengthen your organisation’s overall security posture

Demonstrate your commitment to cyber security and resilience

Gain independent assurance of your security controls

Prioritise remediation based on real-world attack scenarios

Coller Capital – Web Application Penetration Test

This web app penetration assessment has been vital to our business. Not only were we taken through any potential risks, but we were also given thorough guidance on how to mitigate them, in a language we were able to understand. Being given this information has been invaluable in ensuring our data is protected.

Senior Cyber Security Manager

Learn more

Choose your penetration test

With a variety of penetration testing solutions available, it’s not always clear which type of assessment is right for your organisation. That’s why Stripe OLT offers a range of core penetration testing services designed to uncover vulnerabilities across modern technology environments.

Our core testing areas are outlined below, with engagements tailored to include additional systems, environments and security controls where required. Additional penetration testing focus areas include: servers, software, databases, firewall and physical testing.

Web Application Penetration Test

Identify security vulnerabilities that have stemmed from insecure web development practices.

Test authentication and access controls to identify potential weaknesses

Assess web applications for vulnerabilities such as XSS and injection attacks

Identify insecure server or database configurations supporting the application

Discover weaknesses that could allow unauthorised access or data exposure

Mobile Penetration Test

Assess the security of mobile applications across common platforms, including Android and iOS.

Identify insecure application functionality and configuration weaknesses

Discover vulnerabilities such as insecure data storage, authentication flaws and insecure data transmission

Assess application permissions, APIs and backend services for potential security risks

Identify weaknesses that could allow unauthorised access to application data

Infrastructure Penetration Test

Assess the security of your organisation’s core infrastructure to identify weaknesses that could expose critical systems and services.

Identify vulnerabilities across servers, systems and supporting infrastructure

Assess security controls protecting critical infrastructure components

Evaluate resilience against unauthorised access, lateral movement and privilege escalation

Discover how attackers could exploit weaknesses to compromise systems or access sensitive data

Network Penetration Test

This type of assessment tests both internal and external network perimeters to identify security weaknesses across your organisation’s network infrastructure.

Identify insecure configuration parameters

Assess firewall rules and segmentation controls

Identify unpatched systems and exploitable software vulnerabilities

Assess encryption standards and protocols for potential weaknesses

Cloud Penetration Test

This pen test will detect and exploit security vulnerabilities in your cloud infrastructure.

Identify insecure configurations across cloud platforms and services

Discover risks associated with outdated or unsupported software

Identify weak credentials or access controls that could expose cloud resources

Assess cloud services and configurations for potential security weaknesses

Wireless Penetration Test

Identify and examine the connections between all endpoints and devices connected to your organisation’s Wi-Fi.

Identify vulnerabilities within wireless access points and network security controls

Understand how an attacker could move through your wireless infrastructure, escalating their privileges and compromising your corporate network

Our
Awards

Megabuyte Top 50 Emerging Companies 2024

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Ryan Pullen

Head of Cyber Security

“Effective penetration testing isn’t just about identifying vulnerabilities; it’s about understanding how real attackers think and exposing the paths they would use to compromise your systems.”

The Stripe OLT proven process

Pre-engagement Scoping and Preparation

Before testing begins, we work closely with your team to define the scope, objectives, and testing boundaries. This ensures clarity on what will be tested, when, and how, while aligning the assessment with your business priorities and compliance requirements.

Reconnaissance & Information Gathering

We gather information about your environment, infrastructure and publicly available data. This phase identifies potential targets and helps shape our threat model so the test mirrors real world attack scenarios.

Scanning & Enumeration

We use manual penetration testing techniques and industry leading tools to scan your systems to find vulnerabilities, misconfigurations and exposed services. We also enumerate services, applications and infrastructure components to get deeper into your environment.

Access & Exploitation

Our team simulates targeted malicious attacks to gain access through the identified vulnerabilities. We test how an attacker could get into your systems, escalate privileges and access sensitive data – all without disrupting business.

Expansion & Access Maintenance

We test how far access can be expanded within your systems, how long it can be maintained undetected and what the impact of a sustained breach would be. This phase highlights immediate risks and long-term security gaps.

Reporting

Once testing is complete we ensure your environment is restored to its original state. We provide a clear, jargon free report of all findings, business impact and actionable steps to improve your security posture.

Looking for more information?

Some of the most common questions we are asked by IT leaders…

Planning & Scoping Your Test

What information do I need to provide for a pen test?

To get the most value from a penetration test, it’s important to provide a clear and accurate picture of your environment. We always start with a structured scoping session to define what’s being tested and how.

What you need to provide will partly depend on whether the test is black box, grey box, or white box:

Black box testing simulates an external attacker with no prior knowledge, so we typically only need public-facing details (like IPs or URLs).
Grey box testing involves some internal knowledge, like user credentials or limited access, and gives us a deeper view into application logic and internal controls.
White box testing is the most comprehensive; it may require full documentation, admin access, configurations, or source code, depending on what’s being tested.

Beyond that, we’ll usually ask for:

A list of assets or systems to be tested
Technical contacts for coordination
Any areas to exclude (e.g. production systems during critical periods)
Compliance goals (e.g. Cyber Essentials Plus, ISO 27001, GDPR)
Recent changes or past incidents (to identify areas of concern)

Don’t worry if this feels overwhelming. Get in touch, and we can guide you through it all and help define the right scope for your business.

How long does it take to conduct a penetration test?

This is dependent on the kind of test being performed.

For example, a web application penetration test typically takes around one week, including both testing and reporting. A cloud configuration review may take no more than two days.

More complex, bespoke testing or assessments involving multiple assets or phased approaches can require several weeks to complete.

At Stripe OLT, we define clear timelines during the scoping process and include time for both testing and delivery of your detailed report and remediation workshop.

Will my organisation be disrupted by a penetration test?

There is some risk with penetration testing, but when scoped and managed correctly, disruption is very rare. At Stripe OLT, we take every precaution to not impact live systems, and work closely with your team to make sure everything runs smoothly.

Before we start testing, we will:

Agree on safe test windows
Identify critical systems to exclude
Flag potential weak points where downtime could occur, so you’re fully informed
Secure secondary approval for any high-risk test cases

If anything unusual is found, by us or your team, open communication is key. We’ll stop testing immediately and work with you to figure out what’s going on. If needed, we’ll also provide relevant logs to your internal teams.

Testing Options & Costs

Can I get a one-time pen test, or do I need continuous testing?

You can do a one off penetration test, and for many organisations, this is the right place to start. It’s useful for compliance, testing a new system or responding to a recent change.

But for businesses with dynamic environments, such as cloud platforms or frequent software releases, we recommend considering continuous or scheduled testing. This means regular, automated and manual testing to catch new vulnerabilities as they emerge, so you can stay ahead of the game.

At Stripe OLT, we’ll tailor the approach to your risk profile and budget, whether that’s a one-off or a longer-term testing strategy.

How much does a penetration testing service cost?

There’s no fixed price for penetration testing, because the cost is shaped by the type of test, the size and complexity of your environment, and the level of depth required.

At Stripe OLT, our pricing is built around a transparent, scoped model, taking into account factors such as:

The number of hours needed for testing and analysis
The complexity or criticality of the systems involved
Any travel or on-site requirements
Reporting time, QA, and final delivery workshops
Licensing or tooling required for the specific engagement

Rather than offering a one-size-fits-all quote, we work with you to define the right scope and ensure the cost reflects both the value delivered and the risk reduced.

If you’d like a tailored quote based on your environment and goals, get in touch. We’d be happy to help you scope it out so you don’t over pay for what you don’t need.

What tools are used during a penetration test?

This is dependent on the test being conducted. At Stripe OLT, Tool lists can be provided upon request, but range between port scanners, proxying software, vulnerability assessment tooling, custom tooling in a variety of languages and more.

If you’re looking for a penetration testing company that uses specific tooling, get in touch.

Speak to the experts

Want to understand more about how our team can support your requirements? Fill the form, and we'll be in touch shortly.