The Invisible Text RAG Trap: Why Zero-Font PDFs Hijack Copilots
Originally published by the **Logic42 Sovereign Engineering Practice* at https://logic42.ai/articles/invisible-text-rag-trap-document-copilots.* The invisible text RAG trap is an indirect prompt injection exploit where adversaries embed zero-font or white-on-white text into PDF streams to hijack enterprise document copilots. While human auditors and optical rasterizers see normal contractual terms, naive DOM parsers extract hidden instructions, injecting unauthorized system commands directly in…