As the chair of an ISO committee, I have real trouble believing that this is a PDF file coming directly from ISO. It actually looks like someone got a protected PDF file and tried to unprotect it by “refrying” it through some funky third party software.
Why do I say this? Look at the Document Properties.

Based on our knowledge of ISO's publishing process, the VeryDOC PS to PDF Converter is not software used by ISO for publication. The output is done via a process that ultimately exports PDF from InDesign and has bookmarks.
Scrolling through the document, at page 34 I get the following:

Running the Acrobat Pro Preflight profile Report PDF syntax issues I get the following results:

This is clearly a very bogus PDF file with unknown operators and invalid operands. The problems are so bad that what should otherwise be a relatively simple PDF file, forces Preflight to run out of memory.
Also, running Preflight's List potential font problems profile yields:

The fonts are Type 3 fonts - something you wouldn't normally find in PDF files from ISO and they certainly wouldn't be at 0.18pt.
Bottom line is that this is a very malformed PDF file that I am positive did not come directly from ISO, but rather via some attempt using some very bogus tools to remove document security via “refry” mechanisms.
Sorry, but this file cannot be fixed!