Hi TeamViewer Community,
I just figured that there seems to be a mistake on TeamViewer website. When I tried to download TeamViewer for MAC, I am guided to https://www.teamviewer.us/downloads/ where the downloaded TeamViewer.dmg file loaded as *bleep* Host and the package cannot be opened.

Then I found this page https://www.teamviewer.com/en/download/mac/ that actually works and downloaded installer file actually contains executable installer package.
I guess TeamViewer is upgrading the webpage. Thus I am posting it out to avoid further confusion.