Author here. This is strange, as I only use the Ghost site itself for hosting. I don't do any self-hosting or anything. Until this week, I'd never heard of anyone having troubles, but over on Reddit I saw a long-time reader getting some kind of SSL error, then later it said the site "wasn't available". Now in that thread someone else is getting that "phishing" error.

Time to get ahold of Ghost tech support and see what's going on. Sorry for the troubles!