Hi Nikhil,
Which JRE version are you using? I am not able to see as UNKNOWN publisher in security pop-up. This pop-up use to come for me, when I was using JRE Version 7 Update 45.
It works fine for me now, I am using latest JRE i.e., JRE Version 8 Update 45..
Regards,
Sai Vellanki.