I was attempting to download a book on pandas that spans about 390 pages, and I noticed that the PDF file was 39MB in size. Since I found it on a Chinese university website, I got a bit paranoid about potential hidden executables in the file and decided to cancel the download. Can a plain text PDF of around 400 pages actually be 39MB? And is it possible to hide executable code within a PDF?
4 Answers
Yeah, a PDF can be quite large even if it's just text. Sometimes PDFs need to embed fonts, especially for languages like Chinese that rely on specific character sets. So, a 400-page PDF reaching 40MB isn't surprising at all.
If you're worried about file size, keep in mind that the malicious code can be super small, even less than a megabyte. It’s best to trust the source. If you’re unsure, it’s better to skip it. File size isn't a good indicator of safety.
Identifying malicious code by checking file size can be misleading. Typically, you should expect around 100KB per page for simple text. If the book has images, that could change things. Just keep an eye out for any sketches over scans, they usually take up more space.
Sometimes PDFs are just image-heavy, which can make them larger without being a virus. OCR quality varies, so experimentation might be necessary. I've not encountered virus issues in similar files.
Exactly! Just because a file is big doesn't mean it's harmful. Always check your sources carefully.