Unverified50% confidenceFactExact time
Methods for hiding text in PDF and Word documents include white-colored fonts, extremely small font sizes, invisible layers, Unicode zero-width characters, metadata field embedding, and using PDF's JavaScript to dynamically generate text.
1
Sources
50%
Confidence
Long-term
Relevance
8/16/2026
First Seen
Sources
康州法官发现诉状暗藏AI隐藏指令：提示词注入攻击入侵司法系统
hackernewshackernews8/14/2026
Related Claims
Unverified原生PDF的文字以字符编码形式存储，可以直接复制、搜索和提取，无需OCR；扫描型PDF本质是图像，必须通过OCR技术识别67% similarVerifiedPDF is essentially a page description language oriented toward printing, storing the absolute coordinates of characters rather than semantic structure internally, leading to parsing challenges such as the need for OCR with scanned versions, disordered reading order in multi-column layouts, and loss of row-column relationships in tables.65% similarUnverified攻击者可利用视觉不可见的Unicode特殊字符或白色文字置于白色背景使人工审阅防御失效63% similar
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