Test internal defences before attackers do

What if someone got inside your network. Would your systems hold up? We simulate that exact scenario to find internal vulnerabilities before anyone else can.
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Internal Penetration Testing

Assess the security of your internal network from an attackers perspective

Our consultants simulate insider threats to identify risks across your internal environment. These assessments typically begin with network access and no prior knowledge of your systems. The goal is to uncover weaknesses, escalate privileges and access critical systems that should be protected.

  • Corporate internal network: Testing includes targeting high-value assets such as executive email accounts or financial systems
  • Network segregation testing: Verifying controls between segmented zones to ensure proper isolation and prevent lateral movement
  • Wi-Fi access: Assessing guest, BYOD and corporate Wi-Fi for weak or missing controls including passwords, authentication and network separation
Service detail

Find internal flaws before attackers do

Strong internal security is a key part of your overall posture. Our team helps you uncover hidden risks inside your environment that perimeter defences won’t catch.

Go beyond automated scans

Exploit weaknesses

After gaining network access, our consultants assess your systems from an attacker’s viewpoint. They will attempt to enumerate users, exploit weaknesses, pivot across systems and escalate privileges to evaluate your true risk.

  • Identify vulnerable systems or applications inside your network
  • Find exposed or sensitive data on internal file shares
  • Attempt to escalate privileges including domain administrator access or forest-level control
Our delivery process

How is it delivered

From initial scoping through to reporting and remediation, our team works closely with you to understand your environment and deliver expert testing with minimal disruption. We provide a clear, detailed report that explains the vulnerabilities found, their potential impact on your business and recommended remediation steps to strengthen your security posture.
Pre-engagement planning
We define the scope of the engagement, identify key systems and establish communication channels. Th
Testing
Whether testing is remote or onsite, our consultants keep you informed throughout. Any serious issue
Report delivery and beyond
We provide a high-level summary of issues along with detailed findings and remediation advice. Our reports include reproduction steps and actionable recommendations. We also offer validation testing to confirm fixes are in place and effective.
Benefits

Why partner with Bastion for internal testing

We deliver expert-led testing designed to uncover meaningful risks without disrupting your business operations.
Responsible testing
Our consultants balance depth and precision, running high-impact tests while minimising risk to your systems.
Trusted technical expertise
Our team is highly qualified, holding respected industry certifications such as the OSCP, OSCE3 and CREST CRT. We're also a CREST certified consultanc
Beyond the basics
We go further than domain-level access. Our goal is to uncover every relevant vulnerability within scope to give you a complete picture of your exposu
What comes next

Expand your security coverage

Once internal risks are identified, we help you take the next step with services that build long-term resilience and reduce your attack surface.

  • Prioritised remediation planning to address high-impact findings
  • Follow-up testing to validate fixes and confirm risk reduction
  • Ongoing advisory to improve controls and internal segmentation
Talk to an expert
Executive and Board Security Governance Training
We train executives and boards on their cybersecurity oversight role — focusing on risk framing, accountability, and key governance responsibilities.
Advanced OSINT Training Course
This hands-on course teaches advanced open-source intelligence techniques, tools, and tradecraft for investigations, threat profiling, and situational awareness
Frequently asked questions

Frequently asked questions

From risk assessment to rapid response - we’re with you every step of the way.

What is internal penetration testing?

Internal penetration testing simulates an attack from within your network to uncover weaknesses that could be exploited by malicious insiders or threat actors who have gained internal access. It helps identify vulnerable systems, misconfigurations, and access control issues that perimeter defences might miss.

Why is internal pen testing important if we already do external testing?

External testing checks your perimeter, but internal testing shows what an attacker could do if they got inside. It reveals risks like excessive user privileges, poor network segmentation, and insecure internal systems that external tests won’t detect.

What systems are typically tested during an internal penetration test?

Our team reviews your corporate network, internal servers, Wi-Fi access points, and network segmentation. We also test for vulnerabilities in high-value assets like executive email accounts and shared file systems to uncover critical internal risks.

Will an internal penetration test disrupt our systems?

No. Bastion’s internal testing is carefully planned and controlled to minimise business disruption. We work closely with your team and provide a detailed report outlining risks, impacts and remediation steps - without affecting day-to-day operations.

What will I get at the end of an internal pen test?

You'll receive a comprehensive report detailing each vulnerability identified, how it could be exploited, and practical steps to fix it. This gives your team a clear path to improve internal security and reduce your risk of a serious breach.

Contact us

Talk to an expert

Please call our office number during normal business hours or submit a form below
Where to find us
If you experience a security breach outside normal working hours, please complete the form and we will respond as soon as possible.