I'm running Graphene on a Pixel 6. I lost it and someone opened it somehow and called two of my contacts to give it back.
I'm a bit confused how this even happened. When I got the phone back, they were going through my contacts. I checked app usage stats and they went through a banking app (not missing money), maps, signal, etc.
Is there a way to figure out how they even unlocked my phone?
What I said, a smartphone can never be a secure device and this is why it is crazy to have sensitive data stored in these gadgets. It is certainly unlikely that this person gained access by trying the pins, because the cell phone would be blocked after the third failed attempt, but even so, a computer expert needs seconds to access, bypassing this little protection that cell phones have. You can be happy that your Secure Banking app is better protected, probably with 2FA, coordinate card, ID card or similar. In any case, this mobile phone is already compromised, which makes it necessary to change at least the credentials, better even your phone number (ask your ISP). Also be attentive, since this person may have been honest, but he returned it may also be because he was not interested in the cell phone, but in the address where you live.
The own OS and preinstalled app in a Mobile are extracting your data. This you can only avoid to root it to be able to desinstalar them, but this cause that you must made the security updates by yourself, in rooted phones it isn't automatic. Than use only apps from F-Droid and not from the Store, install an paid AV and use VPN. Only in this way it is somewhat more secure. Better if you use some Linux Mobile.
The own OS and preinstalled app in a Mobile are extracting your data. This you can only avoid to root it to be able to desinstalar them, but this cause that you must made the security updates by yourself, in rooted phones it isn't automatic. Than use only apps from F-Droid and not from the Store, install an paid AV and use VPN. Only in this way it is somewhat more secure. Better if you use some Linux Mobile.