Internal Network Security

Internal Network Penetration Test

An Internal Network Penetration Test evaluates your organization's internal network security by identifying vulnerabilities through real-world attack simulations.

What you'll get:
  • A thorough assessment of internal networks and systems
  • Specialized Active Directory and Azure Active Directory testing
  • Internal asset discover for out-of-date devices such as IoT, printers, phones, ect
  • Optional focus on advanced threats such as Spoofing, EIGRP, GLBP, HSRP, VLAN attacks, and other protocols
  • System configuration and network segmentation hardening recommendations
  • A comprehensive report with detailed findings and remediations steps
  • Remediation and patch validation testing to confirm vulnerability fixes

Book A Meeting|

Loading...

What is Internal Network Penetration Testing?

Internal network penetration testing is a security assessment that simulates an attacker who has already gained access to your corporate network — whether through a compromised employee workstation, a malicious insider, or a breached VPN connection. The goal is to determine how far an attacker could move laterally through your environment, what sensitive systems and data they could access, and whether your internal security controls can detect and prevent the attack.

Unlike external testing that focuses on perimeter defenses, internal penetration testing examines the security of your Active Directory environment, network segmentation, internal services, endpoint configurations, and privilege escalation paths. This type of assessment reveals the real-world impact of a breach by demonstrating what an attacker could achieve once inside your network.

DarkPoint Security's internal network penetration tests provide organizations with a clear understanding of their internal attack surface and concrete recommendations for hardening their environment against lateral movement and privilege escalation attacks.

Internal network security testing

Why Your Organization Needs Internal Network Penetration Testing

Most organizations invest heavily in perimeter security but leave their internal networks vulnerable. Studies consistently show that the majority of data breaches involve lateral movement within internal networks after the initial compromise.

  • Assume Breach Readiness — Validate whether your internal security controls can detect and contain an attacker who has bypassed perimeter defenses
  • Active Directory Security — Identify misconfigured AD permissions, Kerberoastable accounts, delegation issues, and attack paths to Domain Admin that attackers commonly exploit
  • Compliance Requirements — Satisfy PCI DSS, SOC 2, OSFI, and other frameworks that require regular internal security assessments
  • Network Segmentation Validation — Verify that your network segmentation actually prevents lateral movement between sensitive environments such as cardholder data zones, production servers, and corporate networks

Our Internal Network Testing Methodology

Our internal network penetration tests follow a structured methodology based on industry standards:

  • PTES (Penetration Testing Execution Standard) — Provides the overall engagement framework from scoping through reporting
  • NIST SP 800-115 — Guides our technical security testing procedures for network-level assessments
  • OSSTMM — Supplements our approach with operational security metrics and controls verification

The assessment begins with internal reconnaissance to discover hosts, services, and network topology. We then perform vulnerability identification across discovered assets, followed by exploitation of identified weaknesses. A critical phase involves Active Directory attack path analysis to identify routes to domain compromise. Finally, we attempt lateral movement and privilege escalation to demonstrate the full impact of discovered vulnerabilities.

Testing Coverage

Our internal network penetration tests cover a comprehensive range of attack vectors:

  • Active Directory and Azure AD enumeration and exploitation
  • Kerberoasting, AS-REP Roasting, and credential attacks
  • NTLM relay and coercion attacks
  • Network protocol poisoning (LLMNR, NBT-NS, mDNS)
  • VLAN hopping and network segmentation bypass
  • SMB, RDP, SSH, and service exploitation
  • Password spraying and credential reuse
  • Group Policy enumeration and abuse
  • Privilege escalation (local and domain)
  • Lateral movement through compromised credentials
  • Internal web application and database discovery
  • IoT device, printer, and phone discovery and exploitation
  • Certificate abuse and ADCS attacks
  • Sensitive data exposure on file shares and databases
  • Routing protocol attacks (EIGRP, GLBP, HSRP)
  • Endpoint protection bypass assessment

Industries We Serve

DarkPoint Security delivers internal network penetration testing to organizations across Canada's most regulated sectors. We understand the unique compliance requirements of financial services and banking (PCI DSS internal scanning, OSFI B-13 technology risk guidelines), healthcare (PIPEDA, provincial health information acts), technology and SaaS companies (SOC 2 Type II, ISO 27001), and government and public sector organizations. Our reports are tailored to demonstrate compliance with the specific frameworks relevant to your industry.

Why Choose DarkPoint Security

  • Manual-First Approach — Our testers go beyond automated scanning to perform hands-on Active Directory attack path analysis, credential attacks, and lateral movement that tools alone cannot replicate
  • Certified Security Professionals — Our team holds OSCP, CEH, and CISSP certifications, ensuring deep expertise in network exploitation and Active Directory security
  • Proven Vulnerability Research — Our published CVEs demonstrate our ability to discover novel vulnerabilities in enterprise products, including network appliances and VoIP devices
  • Canadian Data Residency — As a Toronto-based firm, all testing data and reports remain within Canadian jurisdiction, addressing data sovereignty requirements
  • Remediation Validation — Every engagement includes follow-up retesting to confirm identified vulnerabilities have been properly remediated

Frequently Asked Questions

External penetration testing evaluates your perimeter defenses from the internet — firewalls, public-facing applications, and exposed services. Internal penetration testing simulates an attacker who is already inside your network, focusing on lateral movement, Active Directory exploitation, privilege escalation, and network segmentation. Both are essential for a complete security assessment, as they address different threat scenarios.

We can perform internal testing either on-site at your office or remotely via a secure VPN connection. For remote engagements, we typically connect through your existing VPN infrastructure or a dedicated testing appliance placed on your network. We work with your IT team to establish the access method that best fits your environment and security requirements.

We take great care to minimize disruption during internal testing. Our team coordinates with your IT staff to understand critical systems and schedules. We avoid denial-of-service testing and destructive actions unless explicitly authorized. If we discover a vulnerability that could impact system availability during exploitation, we report it without exploiting it and discuss the approach with your team first.

A typical internal network penetration test takes 1 to 3 weeks depending on the size of the network, number of hosts, and scope of the engagement. Smaller environments with fewer than 100 hosts may require only a week, while large enterprise networks with multiple domains and VLANs may need additional time. We provide a detailed timeline during the scoping phase.

Our report includes an executive summary, a detailed attack narrative showing the path from initial access to domain compromise, individual vulnerability findings with severity ratings and CVSS scores, evidence screenshots, and prioritized remediation recommendations. We also include a network topology assessment and segmentation analysis. A debrief call is provided to walk your team through the findings.

Related Services

Strengthen your security posture with complementary assessments:

Related Articles

Learn more about penetration testing from our blog: