We are in the process of releasing 9.6.6 to the classic Home Edition user base. This update in a maintenance patch including some improvements for compatibility with macOS High Sierra (10.13) when using on-demand scans with APFS volumes. The update also includes a new threat detection engine (3.70.2).
All existing installations should get this update within the next hour or two.
This is a good time to remind everyone that although we'll continue to offer maintenance updates for this product periodically this "classic" Home Edition version of Sophos Anti-Virus, but you should not expect this will last forever. We really encourage everyone to look at upgrading to the new Sophos Home product, as that version will get all the new consumer-oriented features going forward.
Get started with Sophos Home today: https://home.sophos.com
Note: The standalone installer is no longer available.