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Speak to an expert 03333 233 981

Speak to an expert 03333 233 981

Why choose Citation Cyber?

Expert support

Testing by CHECK-approved and CREST-certified penetration testers.

Single platform

Delivered through Atlas, your one stop shop for managing cyber risk.

Every sector

SMEs, public sector, care providers, early years, education, professional services.

What is internal infrastructure
penetration testing?

Internal infrastructure penetration testing simulates the actions of an attacker who has already gained access to your network. That could be through a compromised device, stolen credentials, or malicious insider activity.

Testing focuses on what happens next: how easily an attacker could move around your network, escalate privileges, access sensitive systems, or gain full control of your domain.

Why internal infrastructure penetration testing matters

Many serious breaches happen after an attacker gets inside the network, often through phishing, compromised credentials, or third-party access.

Internal penetration testing helps you:

  • Understand how exposed your internal network is
  • Find weaknesses that allow lateral movement and privilege escalation
  • Reduce domain compromise and further disruption  risk
  • Strengthen defences against insider threats and breached accounts
  • Validate existing security controls and monitoring

 

What’s included in our internal

penetration testing services

Network mapping and asset discovery

Internal services, systems, and trust relationships identification

Exploit identified vulnerabilities where safe and appropriate

Testing for privilege escalation and lateral movement

Authentication, access controls, and segmentation assessment

Evaluate how an attacker could reach critical systems

Prioritised risks plus practical remediation guidance

Free retests on high and critical vulnerabilities

Our internal penetration testing process

Assess and secure your internal network in five clear steps with our CHECK and CREST certified ethical hackers.

A woman with short dark hair is using a tablet while standing in a server room, wearing a grey sweater and an identification badge.
1

Discovery phase

We learn about your environment, users, goals.

2

Pre-testing

Confirm scope, approach, and logistics, including setup.

3

Testing

UK-based experts exploit vulnerabilities to show current risks.

4

Reporting

You’ll receive a clear breakdown of findings, fixes and actions in Atlas.

5

Review, retest

Walk through the results and retest high/criticals at no extra cost.

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How we test your internal environment

Before any testing takes place, you’ll have a kick off call with an ethical hacker to walk you through what we’ll do, discuss potential risks, and answer any questions you have.

White box

We test with full knowledge of your external systems to understand how far an attacker could go if your perimeter was breached.

Best for: Deep assurance, compliance, and mature IT environments.

Grey box

We test with limited information to simulate the access a trusted third party or compromised user might have.

Best for: Practical risk insight without full system exposure.

Black box

We test with no prior knowledge, just like a real attacker scanning the internet for weaknesses.

Best for: First-time testing or establishing a baseline.

What happens next?

After the assessment, you’ll get a clear, actionable report that shows what’s vulnerable, how serious it is, and what to fix first in our all-in-one platform Atlas.

A collection of three pages from a web application security assessment report, featuring charts and summary tables categorizing findings and risks.

In your report, you’ll see:

High-level executive summary

Technical and remediation summaries

Vulnerabilities with clear risk ratings (Citation Score & CvSS Score)

Description, impact, evidence of each vulnerability

Short- and long-term remediation guidance

Technical detail for your IT/MSP

Free retest results

What is CHECK-certified penetration testing?

CHECK is the National Cyber Security Centre’s (NCSC) approved scheme for penetration testing, and the UK government’s standard for how testing should be done.

For many organisations, CHECK certification is also a requirement for public sector work, compliance, and reassuring clients and stakeholders that security has been properly tested.

Logo indicating an assured service provider associated with the National Cyber Security Centre, highlighting CHECK Penetration Testing.

Protect your systems all year round

A penetration test shows you where you stand today, but threats don’t stand still. Reduce your risk of a security breach with vulnerability scanning that provides 365 days’ protection. So you can identify and fix vulnerabilities throughout the year.

UK breaches 2024

£3.29m

Average breach cost

8.58m

Cyber crimes of all types

43%

Businesses faced an attack

What you can test

Our penetration testing services let you test anything that connects to the internet. These tests uncover vulnerabilities and allow us to deliver tailored recommendations that safeguard sensitive data and the systems supporting it.

Penetration Testing

Identify risks with expert-led simulated attacks to protect your data and systems.

Cyber Essentials Certification

Achieve Cyber Essentials certification to defend against common threats, whatever your business size. 

Employee Awareness Training

Empower your team to be your first line of defence with easy, interactive training.  

Phishing Simulator & Bespoke Campaigns

Simulations to teach your staff how to spot and stop phishing scams easily.

Intelligent Monitoring & Vulnerability Scanning

Stay protected between pen tests with continuous scanning and real-time breach alerts.

Cyber Security Consultancy

Tailored advice for compliance, ransomware plans, and board-level cyber support.

Cyber Security Compliance  

Simplify policies with NCSC-approved templates and hassle-free management tools.

Cyber Liability Insurance

Show insurers your safeguards and enjoy peace of mind with reduced premiums.

Frequently Asked Questions

Will internal penetration testing disrupt my business or cause downtime?

Citation Cyber work with you to make sure any penetration test causes minimal disruption to your operations. If you want, we’ll test in staging or development environments and share issues in real time so you can act quickly.

How long does an internal infrastructure penetration test take?

Internal infrastructure penetration tests take different amounts of time depending on your infrastructure and systems. Get in touch with our team to understand how long yours might take.

How technical is the report?

Your penetration testing following up report has all the information your need to understand what vulnerabilities you have and how to fix them. If you need help understanding the report and what it means, we can walk you through the findings and give you any information you need.

Can you work with our MSP or IT supplier?

Yes, we work closely with MSPs and IT suppliers to support their work and understand your systems. We can also share remediation information and advice following an engagement.

How much does an internal penetration test cost?

How much an internal infrastructure penetration test costs depends on how long the testers need to complete the engagement. That depends on your infrastructure, systems and the testing type you choose. Get in touch with our team to find out about pricing.