To ensure the file hasn’t been tampered with, you can verify the checksum:
Want to keep this version separate from your main browser? You can run Firefox 48.0.2 directly from the DMG without installing: Firefox 48.0 2 Mac Download
: Firefox 48.0.2 is the last "standard" release that works on Mac OS X 10.6 (Snow Leopard) , 10.7 (Lion) , and 10.8 (Mountain Lion) . To ensure the file hasn’t been tampered with,
The gradual rollout of multi-process Firefox began here, improving responsiveness. Firefox 48.0 2 Mac Download