Yeah this can be a bit scary if your not familiar with proactive, easy to think it's a virus or something creepy taking over your phone without your knowledge, I saw this too on the public beta and at first I was like what the heck is that small icon since I was not expecting it and wasn't until later when I read about all the new features in iOS9.
I don't see how anyone could be scared of a virus in iOS or the icons considering Handoff uses a similar UI.