Penetration Testing Services

Penetration testing is the structured, ethical simulation of real-world attacks against your infrastructure, applications, and people. The objective is not to find vulnerabilities — it is to demonstrate whether your defences withstand a determined adversary, and where they don't, exactly how an attacker would exploit the gaps.

We have delivered over 400 penetration tests across financial services, healthcare, SaaS, manufacturing, and public sector clients in the UK and USA. Our methodology aligns with OWASP, NIST SP 800-115, PTES, and the MITRE ATT&CK framework.

What We Test

External Network Penetration Testing

Internet-facing infrastructure exposed by your perimeter — VPN concentrators, mail gateways, web proxies, public APIs, exposed administrative interfaces, and any cloud workload directly addressable from the internet. We map your external attack surface using both authoritative records and OSINT, then test what we find for exploitable vulnerabilities and misconfigurations.

Typical findings include exposed administrative interfaces, weak SSL/TLS configurations, leaked credentials in code repositories, exploitable software running on internet-facing infrastructure, and authentication bypass vulnerabilities in custom web applications.

Internal Network Penetration Testing

Once an attacker has a foothold inside your network — through a phishing email, a stolen laptop, a compromised VPN credential, or a malicious insider — what can they reach? Internal testing answers that question. We simulate post-compromise lateral movement, privilege escalation, and data exfiltration from a typical employee workstation perspective.

Common findings: Active Directory misconfigurations (see our detailed analysis of AD attack paths), unsegmented networks allowing free lateral movement, weak service account passwords, and exposed administrative shares.

Web Application Penetration Testing

Custom web applications are the most common entry point in modern breaches. We test against the OWASP Top 10 and the OWASP Application Security Verification Standard (ASVS), focusing on business logic flaws, authentication and session management, access control, and data handling — the areas automated scanners typically miss.

API Penetration Testing

REST, GraphQL, gRPC, and SOAP APIs receive specialist testing aligned with the OWASP API Security Top 10. Particular attention to broken object-level authorisation (BOLA), broken function-level authorisation, excessive data exposure, and mass assignment — vulnerabilities that are common in API designs but invisible to traditional web application scanners.

Mobile Application Penetration Testing

iOS and Android applications tested against OWASP MASVS. Static binary analysis, dynamic runtime testing with Frida and Objection, certificate pinning bypass, secure storage analysis, and backend API testing. See our updated technical analysis of certificate pinning bypass techniques.

Our Methodology

Every engagement follows a four-phase methodology:

1. Scoping & Threat Modelling — define attack surface, business context, and risk appetite using STRIDE and PASTA methodologies
2. Active Assessment — manual testing supplemented by OffSecAI automation; every finding validated by a human analyst
3. Analysis & Correlation — findings cross-correlated for attack chain potential, calibrated against live threat intelligence
4. Report & Remediation — executive and technical reports with prioritised roadmaps; free retest within 90 days included

UK & USA Coverage

We deliver penetration testing services to clients across both the UK and the USA. Engagements can be conducted remotely from our UK and US offices, or on-site where physical access testing or sensitive environments require it. Reports and evidence are aligned with the regulatory framework of your jurisdiction:

• UK clients: UK GDPR, NIS Regulations / NIS2 (where applicable), NCSC CAF, ICO breach notification requirements
• US clients: SOC 2 Type II controls, HIPAA Security Rule, GLBA Safeguards Rule, PCI-DSS, state breach notification laws, SEC cybersecurity disclosure rules

We hold ISO 27001 certification and our methodology aligns with both CREST (UK) and PTES (international) standards.

What You Receive

• Executive summary — board-level narrative of business risk, written for non-technical readers
• Technical findings report — every finding documented with reproduction steps, screenshots, CVSS 3.1 scoring, and remediation guidance
• Remediation roadmap — prioritised by exploitability, business impact, and remediation effort
• Direct analyst access — the testers who found the issues are available to your team for clarification, walkthroughs, and remediation guidance
• Free retest — 90 days from the date of report delivery; we re-test remediated findings at no additional cost

Compliance Alignment

Our penetration testing reports support evidence requirements for:

• ISO 27001 (Annex A 8.8 — management of technical vulnerabilities)
• SOC 2 Type II (CC4.1, CC7.1 control evidence)
• PCI-DSS (Requirement 11.4)
• HIPAA Security Rule (technical safeguards evaluation)
• Cyber Essentials Plus (vulnerability assessment evidence)
• NIS2 Article 21 (vulnerability disclosure and management)