macOS High Sierra 10.13.6 DMG — What it is, why it matters, and how to use it

You might ask: Is a DMG from 2018 still considered "new"?

In the context of macOS, "new" means unmodified and digitally signed by Apple. Over the years, many third-party websites have injected malware, adware, or modified installers into old DMG files. A "new" DMG refers to one that matches the original SHA-1 checksum provided by Apple’s servers. It is a pristine, untouched copy of the installer.

Once you have the verified DMG, follow these steps to create a bootable USB or install directly.