Factory Reset without unlocking phone

[dontpanicbobby]

Is this possible?
It's been bantered around my security office that this is possible if you take out the SIM card.

I argued it's not possible. You'd have to unlock to get to Settings or use a button combination. What do you think?

 

[lvt]

With my HTC 10 you can do a factory reset without having to unlock the phone.

 

[lvt]

It's also possible with my LG G4 too.

 

[dontpanicbobby]

Are you using fingerprint unlocking @lvt?

 

[lvt]

Are you using fingerprint unlocking @lvt?

No, just volume and power buttons combination.

 

[Hadron]

Is this possible?
It's been bantered around my security office that this is possible if you take out the SIM card.

I argued it's not possible. You'd have to unlock to get to Settings or use a button combination. What do you think?

I don't think the SIM is anything to do with it.

However, anyone who knows about recovery mode would know how to reset without unlocking, with or without the SIM. This is why FRP was introduced, because otherwise there was nothing to stop a thief doing this.

The corollary of that is that unless you know the Google account credentials you don't gain anything from doing a reset this way (unless you were doing it just to annoy the owner).

 

[dontpanicbobby]

Well that's a button combination for factory reset but how do you unlock your phone @lvt?

 

[dontpanicbobby]

I don't think the SIM is anything to do with it.

However, anyone who knows about recovery mode would know how to reset without unlocking, with or without the SIM. This is why FRP was introduced, because otherwise there was nothing to stop a thief doing this.

The corollary of that is that unless you know the Google account credentials you don't gain anything from doing a reset this way (unless you were doing it just to annoy the owner).

FRP. I'll have to look into that @Hadron. Will I need a custom ROM?

 

[Hadron]

FRP? Any phone that was released with Android 5 or later already has it, whether it uses a stock ROM or custom.

 

[dontpanicbobby]

I don't have to worry abouth that then.

So where are fingerprints stored? Does a factory reset erase them if you haven't unlocked your phone with a fingerprint @Hadron

 

[Hadron]

This article is a little old, but I expect the fundamentals are unchanged.

As for a reset, I've not done one since storing fingerprints so can't answer from experience. The descriptions I've read are ambiguous on this. The FP data should be removed if the account they are associated to is, so at one level you'd think that a reset removes the account so should clear the FP data too. Except the reset does this in a different way to removing through the android system, and we know that some data associated with it are not removed (the Google account credentials have to be retained for FRP), so maybe that's not a safe assumption? I'm really not sure.

A web search suggested that most people thought they would be, but a lot of those answers seemed speculative rather than authoritative, so I remain uncertain. I think you'll have to set up new fingerprints to use them after a reset, but whether they are genuinely cleared if you reset that way I don't know (it would require the reset be a little more subtle than formatting /data).

 

[dontpanicbobby]

k

 

[lvt]

Well that's a button combination for factory reset but how do you unlock your phone @lvt?

As I said, no need to unlock the phone. You have free access to the Recovery menu.

 

[lvt]

I might sound brutal but it's common on my latest phones (Lenovo, HTC, LG...). Everyone can do a factory reset on someone else's phone.

 

[mikedt]

I might sound brutal but it's common on my latest phones (Lenovo, HTC, LG...). Everyone can do a factory reset on someone else's phone.

Then try and set it up as a new user, and the FRP kicks in.

 

[spman]

If my phone (with password/pattern lock/fingerprint lock) is stolen and someone do the factory reset, does it mean the thief can use the phone like a new phone?

After the thief factory reset, is any of my data still stored inside the phone somewhere? Can I still track the phone location?

I (noob) used to think if a phone has (password/pattern lock/fingerprint lock), the phone is useless for the thief.

Using Samsung Note8.

 

[lvt]

If my phone (with password/pattern lock/fingerprint lock) is stolen and someone do the factory reset, does it mean the thief can use the phone like a new phone?

After the thief factory reset, is any of my data still stored inside the phone somewhere? Can I still track the phone location?

I (noob) used to think if a phone has (password/pattern lock/fingerprint lock), the phone is useless for the thief.

Using Samsung Note8.

No it's not a new phone in strict sense unless the thieves are able to alter your phone's hardware identify like IMEI and MAC address.

 

[lvt]

Then try and set it up as a new user, and the FRP kicks in.

I did it all the time using one of my several Google credentials, nothing happens.

 

[Hadron]

If my phone (with password/pattern lock/fingerprint lock) is stolen and someone do the factory reset, does it mean the thief can use the phone like a new phone?

No. That's the whole point of Factory Reset Protection: unless they have your Google login credentials they can't use it.

After the thief factory reset, is any of my data still stored inside the phone somewhere? Can I still track the phone location?

No and no.

 

[Hadron]

I might sound brutal but it's common on my latest phones (Lenovo, HTC, LG...). Everyone can do a factory reset on someone else's phone.

Every android phone has always allowed recovery access.

And we get a constant stream of posts here from people who have reset their phones but didn't know or remember their Google login and find themselves locked out by FRP.

 

[spman]

No. That's the whole point of Factory Reset Protection: unless they have your Google login credentials they can't use it.

No and no.

What does Google login credentials mean, where/when does the phone require me to input it? After I unlock my phone it seems my phone is already logged into Google from the previous login as I can see my Google contacts list without logging in to Google again.

What is the purpose of factory reset by a thief if my phone has password/fingerprint lock? After the factory reset, the phone is still not usable correct, so what is the point of wasting time to factory reset?

If a phone has password/fingerprint lock, after the thief factory reset, does the phone still has password/fingerprint lock?

 

[Hadron]

What does Google login credentials mean, where/when does the phone require me to input it? After I unlock my phone it seems my phone is already logged into Google from the previous login as I can see my Google contacts list without logging in to Google again.

Login credentials means username and password.

Yes, of course you are logged in if you just unlock it. But if the thief can unlock it it's game over: they have access to your data, they can turn off your internet connection so you can do nothing, they can remove your account from the phone. At that point all you can do is notify your service provider and have the phone blacklisted.

But a factory reset wipes you apps and data from the phone. So after a reset your phone is not logged into Google. However, any phone that was released with Android 5 or later stores your login credentials in a separate secure storage device and requires you to re-enter them after a reset. If you can't do that, you can't log in. This is what's called "factory reset protection".

What is the purpose of factory reset by a thief if my phone has password/fingerprint lock? After the factory reset, the phone is still not usable correct, so what is the point of wasting time to factory reset?

A reset will remove the screen lock (PIN/password/whatever). Their purpose is to protect your data, so if the thief reset the phone to get past the screen lock they also removed your data. But they provided no protection to the hardware: if that was what the thief was after then a reset would give them a clean phone that they could log into with a new account use or sell to someone else.

That is why the factory reset protection scheme was introduced, which is entirely separate from the screen lock. Its purpose is to make the phone unusable after a reset unless they know your Google login, and hence make it less attractive to a thief.

A corollary of this is that if you want to sell a phone you should remove your Google account from it before resetting it. Otherwise the buyer won't be able to use it (we get a log of requests for help from people who have bought phones and found them to be FRP locked).

If a phone has password/fingerprint lock, after the thief factory reset, does the phone still has password/fingerprint lock?

No.

 

[dontpanicbobby]

Thanks folks. You answered my question.
FRP ftw!
The data is gone but they cannot see my stuff unless the thieves know my Google credentials.

The reason I brought this up is I left my phone on a bus and tracked it going from Downtown Boston to East Walpole using Google's Find my device. I was worried sick until I contacted the MBTA, told them I was tracking it, and they used their software to pinpoint the bus and have their driver retrieve it. I guess it must have fallen under the seat.

 

[ocnbrze]

Thanks folks. You answered my question.
FRP ftw!
The data is gone but they cannot see my stuff unless the thieves know my Google credentials.

The reason I brought this up is I left my phone on a bus and tracked it going from Downtown Boston to East Walpole using Google's Find my device. I was worried sick until I contacted the MBTA, told them I was tracking it, and they used their software to pinpoint the bus and have their driver retrieve it. I guess it must have fallen under the seat.

glad you were able to get your phone back.....good call on contacting MBTA.

 

[spman]

Thanks folks. You answered my question.
FRP ftw!
The data is gone but they cannot see my stuff unless the thieves know my Google credentials.

The reason I brought this up is I left my phone on a bus and tracked it going from Downtown Boston to East Walpole using Google's Find my device. I was worried sick until I contacted the MBTA, told them I was tracking it, and they used their software to pinpoint the bus and have their driver retrieve it. I guess it must have fallen under the seat.

As you mentioned the data is gone, does it mean someone did pick the phone to do factory reset on the bus? I guess after he factory reset, the FRP appeared so he decided that it is useless to hold on to the phone since he cannot use or sell, so he left the phone in the bus?