How can I stop an application from updating itself? Not to be confused with applications auto updates.

I have this application as an APK file, once I install the application and choose open it starts working perfectly yet it starts downloading a newest version of itself which I dont want to for a certain reason.



The application is a full screen IPTV application. It runs on an Android box. It can be rooted as it's version 4.2.2. The application has no menus or option, it's not available on the store nor it has a specific name.  

Disabling the "Uknown Sources" is not a good solution as I would have the "install blocked" message popping up every two minutes or less since the application does NOT give up on trying to update itself.





Obviously disabling the Internet access is not a solution.

Is there any solution that does not require modifying the APK file itself? I know nothing about Java development and it is impossible for me to modify the source code unless it can be modified to achieve my goal using a for-dummies software like APK Editor
Maybe you can use an app such as Network Connections which has live capture capabilities to find the IP of the update server your app is accessing.

You can then add an entry to iptables to drop the connections to that IP.

For the changes to persist across reboots you'd need a kernel with init support. So you'd have to check that out as well and instal custom one if needed.

PS: I want to make clear that I have no real experience with actually trying any of it and that my answer is just put together from answers I found on other questions on Android Enthusiasts Stack Exchange. In particular, this one and this one.