How to be sure an Android version is official?

[Glonk]

My dad has bought a used S3 from ebay - is there any way to check whether the Android version running is an official version?

Or to ask it another way - could it have been possible for someone to install a custom rom and make it appear official?

Thanks

 

[Rukbat]

Check Settings/General/About device. That will tell you what ROM, baseband and kernel are in the phone.

 

[Glonk]

OK looks legit - however is it possible that someone could create a custom rom and make it appear official?

Just a bit paranoid to know that this phone has not been tampered with on the software side.

 

[srkmagnus]

OK looks legit - however is it possible that someone could create a custom rom and make it appear official?

Just a bit paranoid to know that this phone has not been tampered with on the software side.

Yes. If you can provide the above requested information we can try and help see if its stock or not. In any event, still perform a factory reset through system settings > security > factory reset.

Also, go into system settings > about phone > software. Make sure it's up to date with the latest available software.