Ok. So, you did have a version of Viber installed earlier? And you uninstalled it by the usual method?
I know of the app, but not more than that. I'm guessing it is an android app?
Double check your OS version. I believe you have stated the software release number, not the OS version, and the OS version is 10.3.2.2876. For most troubleshooting situations, user and BlackBerry documentation refers to OS version, not software release number.
So, to the point. See the following.
Unable to uninstall Android applications after updating to BlackBerry 10 OS version 10.3.2
I think you will find this fits your situation and sounds like you haven't applied the update. If you look in device monitor and the app permissions in settings and still see the Viber there, then that would confirm it.
Scroll down to the solution and apply the update as described.