Guides
Every guide to Prompt injection
Start with the main guides, then go deeper on the parts that apply to you.
Last reviewed against NCSC, OWASP GenAI Security Project and Microsoft Security Response Center. Sources
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The main guides
Risks
The risks prompt injection creates for UK organisations: data leaks, unwanted actions and over-trusted tools, with NCSC, OWASP and vendor evidence.
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Plan
A practical prompt injection plan for UK organisations: map untrusted content, limit tool access, add approvals, keep logs and test, in order.
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Questions
Short, sourced answers on prompt injection: what it is, whether it can be fixed, how it differs from SQL injection and what UK teams should do first.
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About this site
Who publishes this guide to prompt injection, why CyPro Consulting Ltd made it and how its sourced account is kept accurate for UK organisations.
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Your product or situation
Examples
Prompt injection examples from OWASP's catalogue, from a support chatbot to hidden image instructions, with what each means for UK teams.
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Direct vs indirect
How direct and indirect prompt injection differ, why indirect injection is the harder problem for business tools, and what each means for defence.
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Lethal trifecta
The lethal trifecta explained: private data, untrusted content and outward communication. How to check your AI tools and remove one of the three.
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Vs SQL injection
Why the NCSC says prompt injection is not SQL injection, why parameterised queries have no equivalent, and what 'confusable deputy' means in practice.
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Prevention
Prompt injection controls for UK teams: least privilege, human approval, separating untrusted content and logging, from OWASP, Microsoft and the NCSC.
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EchoLeak case
EchoLeak, CVE-2025-32711, was a zero-click prompt injection flaw in Microsoft 365 Copilot. What happened, what Microsoft did and what it teaches.
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Questions people ask
What is it?
What prompt injection means, in plain English: how text fed to an LLM can override its instructions, and why UK organisations should care.
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Can it be fixed?
Can prompt injection be fixed? The NCSC and OpenAI both say probably not completely, so the aim is to cut likelihood and impact. What that means for you.
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Do filters work?
Do prompt injection filters, deny-lists and detection products work? What the NCSC, OWASP and Microsoft say about their value and their limits.
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Detecting it
How to spot prompt injection attempts: what to log, which signals to watch and why failed tool calls matter, based on NCSC and Microsoft guidance.
Read the guideHow CyPro can help
Need a hand planning for this?
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Penetration testing
A focused test of your systems and the controls around them, so you know they hold before an attacker finds out for you.
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Find every internet-facing system you run, including the forgotten ones, and see which are still on a vulnerable build.
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Our SOC analysts watch your systems day and night for the signs of an attack in progress: unexpected processes, new outbound connections, logins that do not fit.
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Incident response
If you may already be compromised, our responders contain it, preserve the evidence, find out what was touched and get you running again safely.
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Plan ahead
Want a plan for your organisation?
Prompt injection only shows up when someone tries it against your own tools. Penetration testing can probe the AI features you run or build, to see what a hostile instruction could reach.