

You can use LibreOffice Draw to edit a PDF. It can actually delete text and images from the PDF. You do need to install all of the fonts that the PDF uses before editing it or they will be replaced with what you do have. That will probably mess up the layout if the replacement fonts are not compatible with the originals.






There are a few flash drives available with hardware write protection. They are hard to find though. Just set the switch to write protect before plugging it into an untrusted device and nothing can be written to it.