There are a few indicators of modified/unmodified devices, depending on what was modified and how.
Depending on the manufacturer and model, some of these indicators are not available.
These should apply to any recent Samsung phone:
- : Go to
About phone ->
As long as the ROM/firmware hasn't been tampered with, it should show
This can be Official, even when using custom ROMs, so it's not the best indicator, but the easiest to access.
- : Hold
Home when powering on the device to boot towards the bootloader (used to install official and custom firmware, recoveries etc) and press
Volume-Up without connecting it to a PC (just to be sure).
It will show some information about the state of the device like
the binary status ("Custom" means it's modified), the system status (I rarely seen this not reading "Official")
or KNOX warranty void status (just voids any warranty around KNOX, not anything else; hardware warranty and non-KNOX software warranty is still valid) that indicates tampering with the system at any point in the past (not even reinstalling an official firmware will reset this).
Devices which utilize
fastboot, can be queried using the
fastboot command (from the Android SDK, but there is a package with only the required files).
The command should be
fastboot flashing get_unlock_ability (not tested, I don't have a device with fastboot capability).