Help Custom Operating System

[Boo5556]

This morning, I turned on my phone in my car. WiFi was off as was mobile data. There was a message on the phone that covered the screen asking if I wanted to install a custom operating system. Of course I could not get to the setting button as the screen was locked with the message. Is this a Samsung upgrade to Lolipop? or something completely different. When I got home, I plugged up the phone, turned it off and now there is no message and nothing updated.