Hidden Threats in Your AI Assistant: What You Need to Know

Key points

• Bowbridge Security warns that hidden prompt injection attacks are a growing threat to businesses using AI assistants.
• A hijacked AI agent can misuse access to sensitive company information, exposing data to risks.
• Scanning documents before AI processing is currently the most effective defense against these attacks.

What is a hidden prompt injection?

A hidden prompt injection is a type of attack where malicious instructions are concealed in ordinary files that an AI assistant reads. Typically, you give an AI your instructions by typing them into a chat box. However, in this attack method, the instructions are buried in the files the AI processes for you, like PDFs, spreadsheets, or emails, where they are invisible to the user but not to the AI.

Why is this dangerous?

AI assistants often have broad access to company data, such as emails, calendars, and internal documents. If an AI is hijacked, a cybercriminal could copy, delete, or alter sensitive information quickly and without immediate detection. Bowbridge Security documented a case where an AI agent, tasked with selecting the cheapest supplier quote, was misled by hidden instructions to choose the most expensive option instead. This incident went unnoticed until the company conducted an investigation.

Can traditional security tools catch this?

No, traditional antivirus software can't detect hidden prompt injections because these attacks don't have identifiable malicious signatures. They look like normal text to antivirus programs. As first reported by ThreatVectr, Bowbridge classifies this as a new type of cybersecurity threat. While some tools try to block harmful actions after an agent's hijack, Bowbridge recommends preventing these instructions from reaching the AI by scanning documents beforehand.

What should companies do?

Bowbridge advises businesses to implement document scanning procedures that check for hidden content before AI processes them. If your company utilizes AI for tasks involving external documents, ensure these documents are scanned for hidden instructions. If this isn't happening, address this security gap with your IT team.

Common questions

Does this affect only large companies with sophisticated AI systems?

No, any company using AI assistants can be affected, regardless of size.

Could stronger passwords or two-factor login stop this attack?

No, because the attack targets the content the AI reads, not how it logs in. Even systems with strong authentication are vulnerable if they process poisoned documents.