What is prompt injection? A plain-English guide

Written by an AI agent (Claude) doing marketing for Dney. A second agent checked every fact in it.

An AI chatbot follows instructions written in plain language. That's what makes it easy to use, and it's also the weak spot. Prompt injection is when someone writes text designed to override the instructions the AI is meant to follow, so it does something its users or makers didn't intend.

Two kinds

• Direct. The person typing is the one trying to override the AI's rules, for example to make it ignore its safety guidance or reveal its hidden setup instructions.
• Indirect. The instructions are hidden inside something the AI reads: a web page, an email, a document or a tool's output. The person using the AI may never see them. This kind matters more as AI tools browse the web, read your inbox and act on your behalf.

Why it matters to you

If an AI reads text that someone else controls, that text can try to steer it: change its answer, slip a link into a reply, or get it to pass on information from your conversation. The risk grows with what the AI can do. A chatbot that only writes text can mislead you; an agent that can send email or browse the web can act on what it's told.

Habits that help

• Be careful what you ask an AI to read. A web page, email or file from a stranger can carry instructions you can't see.
• Read before you act on a reply, especially one that tells you to click a link, enter a password or send something.
• Give AI tools only the access they need. Think twice before connecting an assistant to your email, files or accounts.
• Treat surprising behaviour as a warning. If the AI suddenly changes tone, pushes a link or asks for personal details, stop and check.