How Do I Remove The "Custom Padlock" Logo When Rebooting My Note III.

I had rooted my Note III and started to have issues when I purchased the app XBlast to be able to customize my status bar. I started to receive an error message "system UI has stopped" so I freaked out and restored my phone to factory state, to then find out I was still rooted. I then purchased an app to be able to unroot. But now I have this word " 'custom' with a padlock logo" that I cannot get rid of and have googled but to no avail. I recently purchased my Note III and I am afraid this will void my warranty. Thanking you in advance for any help you can provide.

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