WorkNest Secure
LLM Security Testing
Deploy an LLM security assessment for a structured, human-led review of applications using large language models (LLMs).
LLM security assessments future-proof your AI needs
LLM security assessments future-proof your AI needs
LLM security assessments future-proof your AI needs
As the use of large language models grows, so do the vulnerabilities they pose to organisations in the UK.
With tailored UK Penetration Testing services, our LLM security assessment is designed for organisations that have their own proprietary model or use a third-party plug-in, to identify any weaknesses caused by these before attackers do.
As the use of large language models grows, so do the vulnerabilities they pose to organisations in the UK.
With tailored UK Penetration Testing services, our LLM security assessment is designed for organisations that have their own proprietary model or use a third-party plug-in, to identify any weaknesses caused by these before attackers do.
What is LLM Penetration Testing?
What is LLM Penetration Testing?
What is LLM Penetration Testing?
LLM Penetration Testing identifies weaknesses in large language model applications, uncovering how attackers could exploit vulnerabilities such as prompt injection, data leakage, or misuse.
It is designed for organisations developing in-house models, integrating third-party LLM tools, or building and deploying plugins, helping ensure AI systems are secure, resilient, and ready for real-world use.
Why Choose WorkNest for an LLM Security Test?
LLM security testing strengthens your organisation. At WorkNest, we combine deep technical expertise with practical business understanding to deliver assessments that drives measurable improvement.
CHECK & CREST certified
Have your testing conducted by qualified professionals to ensure the highest possible standards
Expertise and efficiency
We combine human expertise for in-depth analysis with efficient automation for ongoing scanning
GuardNest platform
Simplifies vulnerability management with real-time reporting, remediation tracking, and expert advice.
Compliance support
Supports adherence to relevant industry regulations and standards, helping you avoid the repercussions of non-compliance
Remote testing
Enables thorough internal and external testing without on-site presence or associated expenses
Wide range of expertise
We offer testing across everything from infrastructure and mobile applications to cloud and IoT environments
Our LLM Penetration Testing methodology
We ensure testing has depth and breadth by aligning with recognised methodologies such as CREST, OSSTMM, OWASP, and NIST.
This ensures a structured, consistent approach grounded in cyber security best practices and real-world threat intelligence.
We follow a clear seven-step process designed to deliver rigorous testing, meaningful insight, and practical remediation guidance at every stage.
We define the target architecture and tailor the engagement around your technology stack, risk appetite, and compliance requirements.
We identify the underlying model, middleware frameworks, retrieval pipelines, and tool integrations, probing for system prompt leakage and charting every instruction source the model trusts
We attempt to override your model's instructions through direct and indirect injection techniques, including multi-turn escalation, encoding bypasses, and hidden payloads in content your AI may consume.
We test whether your retrieval pipeline can be poisoned, whether access controls hold across users and tenants, and whether injected content can manipulate model reasoning.
We enumerate connected tools and test for excessive permissions, missing confirmation gates, and whether prompt injection can chain into real-world actions.
We test for cross-site scripting, SQL injection through AI-generated queries, and data exfiltration via tool calls and out-of-band channels.
Findings are mapped to the OWASP LLM Top 10, clearly attributed to either the model layer or the application layer, severity-rated. It is accompanied by concrete remediation guidance, a debrief call, and post-engagement support.
Why should you conduct LLM Pen Testing?
Why should you conduct LLM Pen Testing?
Why should you conduct LLM Pen Testing?
AI systems are developing at pace, so it is essential to test their security to protect your organisations data and information.
Expose insecure functionality in your LLM
Identify how your LLMs can be exploited in practice
Ensure your LLM applications are secure, compliant, and ready for production
Gain full visibility into your LLM risks, from data exposure to model manipulation
AI systems are developing at pace, so it is essential to test their security to protect your organisations data and information.
Expose insecure functionality in your LLM
Identify how your LLMs can be exploited in practice
Ensure your LLM applications are secure, compliant, and ready for production
Gain full visibility into your LLM risks, from data exposure to model manipulation
What our clients say
We’ve always been very impressed with the cyber security services WorkNest provide us. Their professional approach, knowledge and flexibility have ensured they have become a key trusted partner in our supply chain.
Paymentsense
Founder
WorkNest Secure delivered a highly professional and thorough incident response service. Their team’s technical knowledge, attention to detail, and clear communication throughout the process made a complex area easy to navigate. The quality of the analysis and final reporting gave us real assurance and added value to our internal security efforts, minimising the impact to the business.
Shoezone
Head of IT
Uncover and remediate hidden vulnerabilities to improve your organisation’s resilience.
Our Penetration Testing services cover a wide range of endpoint categories, including App, Network, Cloud, Web, and API. We can deliver the Penetration Test you need to get the results you want.
Identify vulnerabilities or misconfigurations in Android, iOS, and cross-platform apps.
Uncover misconfigurations, privilege gaps, and architectural weaknesses before attackers do.
Uncover vulnerabilities and misconfigurations in Windows, macOS, and other desktop software.
Identify weaknesses in your human and physical defences.
