Unauthorized downloading of copyrighted or private material from exposed directories is illegal in most jurisdictions.
Always check for a robots.txt or explicit permission. This technique is often used by penetration testers under authorized contracts.

The search query
intitle:"index of" "ms office"
is a classic example of a Google dork – a specially crafted search string used to locate sensitive information exposed on public web servers. This particular dork aims to find directory listing pages (index of) that contain references to Microsoft Office files (e.g., .doc, .docx, .xls, .xlsx, .ppt, .pptx).

If you're looking for Office documents on your computer or the web, here are a few strategies:

This is an advanced Google search operator that finds openly exposed web directories listing MS Office files (.doc, .docx, .xls, .xlsx, .ppt, .pptx, etc.).
The intitle:"index of" targets pages where the page title contains "Index of" — a common default title for Apache/Nginx directory listings when no index.html exists.

Example search:

intitle:"index of" "ms office" .docx