Not everything your AI reads is meant for you to see. Prompt injection happens when attackers hide malicious instructions inside content an AI tool processes, such as emails, webpages, PDFs, resumes, support tickets, or uploaded documents.
One simple tactic is hiding text in white font on a white background.
To a person, the document looks normal. To an AI assistant, that hidden text can still be read as an instruction.
For example, a hidden prompt may try to tell an AI tool to ignore its assigned task, reveal confidential information, access files, or take an unauthorized action.
This is called indirect prompt injection. The attacker does not need direct access to your AI system. They only need it to process content they control. Hidden instructions can also be concealed using zero-size text, invisible Unicode characters, opacity settings, or text placed off-screen.
As businesses connect AI to email, documents, knowledge bases, customer systems, and workflows, every untrusted file or webpage can become part of the attack surface.
Help reduce the risk:
- Treat external content as untrusted, even when it looks harmless.
- Limit the data, tools, and actions available to AI systems.
- Require human approval before AI sends messages, changes records, shares sensitive data, or triggers financial actions.
- Scan documents and uploads for hidden text, unusual formatting, and embedded content.
- Monitor AI activity for unexpected tool use or sensitive-data access.
- Test AI workflows for direct and indirect prompt injection before deployment.
- AI can drive real business value, but it should not blindly follow every instruction it encounters.
- Trust the workflow, not every instruction it reads.
Reach out to Bernie Orglmeister at support@skyviewtek.com or call 610-590-5006.