> The latest (pocorgtfo16.pdf) is a polyglot that is valid as a PDF document, a ZIP archive, and a Bash script that runs a Python webserver which hosts Kaitai Struct’s WebIDE which, allows you to view the file’s own annotated bytes ...
…well, I start to think that they could do a better job of showing off their savvy and old-school-ness by using a plain old HTML page. Maybe without any CSS - that seems like their style.
Large parts of this document size is due to other pdfs inside the top-level pdf, along with source code to PoC and exploits ... even whole sections of Kant's philosophy (not part of the top level pdf as html) (see my post on https://blog.valbonne-consulting.com/2017/11/01/what-kant-ca...) ... IMO what you removed was the envelope and threw the actual letter away.
Here's a Google Docs mirror, stripped down to 15MiB by removing hidden data:
https://drive.google.com/file/d/1DASC25AIlHPdzOYs2-eB3iVqfjN...
@edit re: why would anyone remove the hidden data?
It makes sense when you mostly want to read the thing and/or put it on an e-book reader. I'm not saying you HAVE to use this version, it's just that if you don't plan to look at the hidden data at first, I'd download it.