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How PDFs hide text, why hidden instructions are aimed at AI reviewers, and how to check a file for both. Plain explanations of the mechanisms this scanner detects.
10 Places Text Can Hide Inside a PDF
A tour of the ten spots where a PDF can keep text — or whole payloads — off the page while leaving it fully readable to software, and how to tell a benign case from a deliberate one.
July 7, 2026
The White Font Résumé Trick — and Why It Backfires
Padding a résumé with invisible white keywords used to fool keyword filters. Against modern parsers and AI screeners it is more likely to sink your application than help it.
June 30, 2026
PDF Prompt Injection: Hidden Instructions Aimed at AI Reviewers
How authors hide instructions inside a PDF to steer the AI tools that read it — the mechanism, who it targets, and how to detect it.
June 16, 2026
How to Check a PDF for Hidden Text
Practical ways to find text that a PDF hides from your eyes but keeps readable to software — from a quick Ctrl+A test to a structural scan.
June 2, 2026