Analysis · curated 21 Sep 2026
AI Blog: Prompt Injection – The Attack Hiding in Your Documents
First reported sumproduct.com
Coverage timeline
Single-source analysis — first reported, latest, and curated coincide.
Why it matters
Indirect prompt injection turns everyday documents and emails into an attack surface as AI agents gain the ability to read, reason and act on an organisation's behalf, potentially leaking confidential data or taking unapproved actions.
A SumProduct AI blog explains prompt injection for finance teams, distinguishing direct injection (harmful instructions typed into a chat) from indirect injection (malicious instructions hidden in documents, emails, PDFs or web pages that an AI assistant later reads and acts on). The piece cites Microsoft's descriptions and demonstrations of hidden prompts in Word documents and webpages manipulating AI assistants, and warns of risks like confidential data exfiltration when agents have access to email and finance systems.