I have Android phone that fails to boot after working happily some time.
I'm trying to install official firmware update zip from manufacturer's site, but update fails with errors:
E: footer is wrong E: signature verification failed E: install package error, result = 7
Google results suggest that official updates can fail integrity verification only if the device is rooted (yes, I've re-downloaded the update several times, the file is ok). As the phone does not boot, I cannot use the "root check" app or terminal etc. On top of the recovery menu, after the ROM version (I guess) there's a line: user/test-keys.
Is this a sign that the device is rooted?