Looks like you're getting flagged because you don't have a large number of users downloading the software, perhaps? A feature of comprehensive antimalware software like N360 is that it looks at what its users are downloading and how safe it's been in the past (at least that's how I understand it). Not sure whether you can do anything about that from your end.
] explains the Norton 360 message. Near the bottom is information about new (and perhaps infrequently downloaded?) files. It also provides a link
] for developers to get their software whitelisted.