However, if you do not want to do that, you can always open PDF files in Protected View in Word. It helps you block any macros from running right after opening the file in Word.

If you do not want to open PDF files externally when using Google Chrome, you can follow this guide. This detailed guide explains how you can allow or block Google Chrome from opening PDF files ...

If you keep Chrome up-to-date without changing any settings, any PDF you download may open within the web browser by default.