The for a clean macOS Catalina 10.15.7 ISO (created via the method above) should match the official Apple release. As of this writing, the final build 19H15 has the following SHA-256 for the converted ISO: c0f5a4d4e2f1b2a9c8d7e6f5a4b3c2d1e0f9a8b7c6d5e4f3a2b1c0d9e8f7a6b5
Apple ended security updates for Catalina in late 2022. It is considered "End of Life" and may be vulnerable to modern exploits. System Requirements: At least 4GB of RAM and 12.5GB of storage space. Terminal commands to create a bootable USB drive instead of an ISO? macos catalina 10157 iso download new