Could not find how to do it with qpdf or pdftk or even a gui tool.
Edit:
Solution pdftk A=oldpdf.pdf cat A output newpdf.pdf
This removes all metadata and also the attachments.
From Wikipedia, the free encyclopedia
Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is typically packaged in a Linux distribution (or distro for short).
Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy.
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I forget exactly what I did, but I think I used okukar. It showed the attachments then it just selected them all and copied them to the desktop.
It might have been one of the web browsers, but I’m pretty sure it was okular as i couldn’t do it on windows.
If you have a better solution, please let me know.
I am talking about removing them from pdf. For extracting them this works
pdftk [pdf_file.pdf] unpack_files.I've used LibreOffice Draw before to remove content from PDF files without reprinting