Rating:
As the docx contained only 1 page and there was nothing of interest there, I looked up in macros.
I found a big macro, which looked like an encoded file.
It looked like a function is used repeatedly and it decodes the string to BASE64.
So, I combined the string, used BASE64 decoder on it and got the whole macro for analyzing.
In the macro, there were some parts which were reversed and also many other transformations like regex and string concat were done.
After carefully reading the file and applying the inverse transformations, we can find out the flag.
Flag : CHTB{maldocs_are_the_new_meta}
You can find the extracted macro in my git repo.
