External Network Penetration Testing
Simulate an attacker targeting your internet-facing systems from the outside.
What this assessment covers.
Your external network perimeter is the first line of defence against internet-based attacks. DERISK’s External Network Penetration Testing service simulates an attacker targeting your internet-facing systems from the outside, identifying perimeter weaknesses before they can be breached.
We scan perimeter defences, identify exposed services, and attempt to breach your external boundary to uncover weaknesses before real attackers do. Our testing covers external hosts, firewalls, VPN gateways, exposed services, and perimeter security controls.
All findings are published in real time to the DERISK PTaaS portal with remediation guidance, giving you a clear picture of your external security posture from an attacker’s perspective.
How we test.
A structured, expert-led methodology from initial reconnaissance through to real-time reporting and remediation guidance.
- 01
External Asset Discovery
We enumerate every internet-facing asset tied to your organisation — external IPs, domains, exposed services, and perimeter devices — to build a complete inventory of your external footprint.
- 02
Perimeter Scanning & Service Identification
We scan perimeter defences, identify exposed services and open ports, and fingerprint technologies running on each external asset to understand what an attacker would target first.
- 03
Vulnerability Identification & Exploitation
We identify and exploit vulnerabilities in exposed services, firewalls, VPN gateways, and perimeter devices to determine what an attacker could achieve from the outside.
- 04
Perimeter Breach Simulation
We attempt to breach your external boundary, chaining discovered vulnerabilities to simulate how an attacker could gain unauthorised access to your internal network.
- 05
Real-time findings published to the DERISK PTaaS portal
External vulnerabilities and breach paths are published live to the PTaaS portal with evidence and remediation guidance for immediate action.
- 06
Reporting & Remediation guidance
You receive a detailed report with risk-rated findings, evidence of exploitation, and prioritised remediation guidance covering external network controls.
Why teams choose us.
Expert-led, manually validated, and delivered through the DERISK PTaaS platform for continuous visibility and rapid remediation.
Outstanding Features
- ✓Complete external network coverage including perimeter hosts, firewalls, and VPN gateways
- ✓Real-time findings and reporting through the DERISK PTaaS platform
- ✓Perimeter breach simulation from an attacker’s perspective
- ✓Exposed service and vulnerability identification across your external footprint
Why Choose Our Service?
- ▸Perimeter security: Identify and close weaknesses in your external boundary before real attackers exploit them
- ▸Realistic simulation: Testing reflects real-world external attack techniques targeting internet-facing systems
- ▸Attack path analysis: Understand how external vulnerabilities could lead to internal network access
- ▸Continuous visibility: Track findings, remediation, and retesting through the DERISK PTaaS platform
Frameworks & standards.
Testing is aligned with industry-recognised frameworks and standards to ensure comprehensive, repeatable coverage.
What you receive.
Everything you need to understand, prioritise, and remediate findings — delivered through the platform with ongoing validation.
External Network Pentest questions.
What is in scope for an external test?
Everything reachable from the internet: public IP ranges, exposed services and management interfaces, VPN and remote access gateways, edge devices, and the authentication in front of all of it.
How is this different from attack surface testing?
External network testing goes deep on the assets you scope. Attack surface testing goes wide to find the assets you did not know you had. Run attack surface discovery first if you are not confident your inventory is complete.
Do you need our IP ranges?
Yes, for a scoped external test. We will also report anything we discover that appears to belong to you but was not on the list — that is usually worth knowing.
How quickly will we see results?
Initial confirmed findings appear on the DERISK platform within 8 hours of kickoff, critical issues are validated and published within 2 hours of discovery, remediation retests complete within 24 hours, and the full report lands within 2 business days of engagement close.
Often scoped together.
Network Pentest
Simulate real-world attacks across your external, internal, AD, and wireless networks.
Attack Surface Pentest
Discover every exposed asset before attackers do.
Internal Network Pentest
Assess what an attacker could achieve once inside your network.
Vulnerability Assessment
Systematic scanning to identify and prioritise known weaknesses.
Ready to secure your assets with External Network Pentest?
Get in touch with DERISK to schedule an assessment or learn more about how our expert-led testing can strengthen your security posture.
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