Always obtain macOS installers directly from Apple via the App Store, softwareupdate , or a trusted Mac from a friend. If you must download a DMG from third parties, verify its SHA hash, scan for malware, and never disable Gatekeeper.
softwareupdate --fetch-full-installer --full-installer-version 10.15.7 The installer will appear in your Applications folder with full cryptographic signatures. This tool lists all available macOS versions from Apple’s CDN: hot download macos catalina 10157 dmg
shasum -a 256 /path/to/your/catalina.dmg ecc7cfa6b036450c4da2bd0a7c4a38afb2784ab6b5a62e5ae44e1c78c577bd24 (Matches the full installer – actual DMG may vary depending on source) Always obtain macOS installers directly from Apple via
Last updated: October 2025 Tools used: Terminal, Malwarebytes, Apple Software Update verify its SHA hash