[Q] Secure N7 from physical access - Nexus 7 Q&A, Help & Troubleshooting

Hi,
I understand that if a person get physical access to the device, even if it is encrypted and password protected, access can be obtain by connecting the tablet to a computer.
This could be done even if the N7 is not rooted neither debugging mode is on and fast boot is locked.
Thanks.
Sent from my Nexus 7 using xda app-developers app

My concern is the following one:
The Nexus root kit allow to make a back up of the device, to unlock fast boot (That step will wipe the device), root the N7.
I understand that these steps can be done without N7 password.
When access in root mode, malicious code could be installed.
Nexus root kit allow you to restore the backup previously done, unroot and re-lock fast boot.
If what I state is correct, a person with physical access to the device can do whatever he wants to do. The user will have no way to be aware of it.
There is a way to protect a N7 against that kind of attack?
There is a way to protect access to fast boot or to disable access through USB?
Sent from my Nexus 7 using xda app-developers app

The way I understand it, I may be wrong though.
If you keep the boot loader locked, a malicious person would inevitably have to erase everything on the device to unlock it to root it.
Now if they made a backup first using the tool kit and restored when they were done, I feel they may undo everything they tried to put on your device.
Granted they would have a complete backup of your device on hand after everything's said and done
If physical security is a concern, I'd suggest having your information you want to keep safe completely off the device, using a cloud service, and inputting your password into such apps all the time.
Sent from my Nexus 7 using xda app-developers app

If I turn on pattern lock (haven't tested with pin, password, face, but I don't know why it would be any different), and connect N7 to the computer, it won't connect. As in, I still see the Nexus 7 device in my computer, but when I click on it, it displays nothing. Only once I enter the pattern, files appear.
Of course, once you enter the pattern, you will gain access to files, even if you relock it (while still connected - once you disconnect, you will have to reenter the pattern)
You can encrypt the tablet in Security settings, and while I don't really know what that does, it should make the backup file unreadable without a password, otherwise this feature is useless.
And I think if you disable USB debugging, you can make installing ROMs and stuff not very possible (but I'm not sure - I just assume, since every flashing tutorial starts with 'enable USB debugging')
edit: http://support.google.com/android/bin/answer.py?hl=en&answer=2425151

truehybridx said:
Now if they made a backup first using the tool kit and restored when they were done, I feel they may undo everything they tried to put on your device.
Granted they would have a complete backup of your device on hand after everything's said and done
Click to expand...
Click to collapse
Thanks for your response.
Sorry I miss explain the chronology:
The attacker switch off the device (could be done even if screen locked)
Reboot to the boot loader
Make the back up with the Nexus Root Kit. --> No password required, correct?
Unlock boot loader --> Device wiped.
Root the device
Restore the backup
Include malicious code
Unroot
Re-lock
If any one can confirm what stated is correct and if there is a way to prevent it.
Sent from my Nexus 7 using xda app-developers app

issak42 said:
You can encrypt the tablet in Security settings, and while I don't really know what that does, it should make the backup file unreadable without a password, otherwise this feature is useless.
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Click to collapse
The encryption only cipher apps and other personal data. It does not cypher the system files... To bad
Sent from my Nexus 7 using xda app-developers app

Honestly, what are you afraid of happening? What do you keep on your device that would make someone go to the trouble to do this? They wouldn't even be able to boot into the OS if it was encrypted. The encryption is your best bet. Or, just don't let the device out of your sight (or pocket).
Sent from my Nexus 7 using Tapatalk HD

korockinout13 said:
Honestly, what are you afraid of happening? What do you keep on your device that would make someone go to the trouble to do this? They wouldn't even be able to boot into the OS if it was encrypted. The encryption is your best bet.
Click to expand...
Click to collapse
We need to secure several N7 that will be use by top management. We choose the N7 because no physical ports (unless the USB...). The back of the device will be glued, we will use a tailored version of Android (no google services at all) plus VPN for all data connection but we still get the physical access flaw issue.
Re: encryption
It does not cipher system file.
Sent from my Nexus 7 using xda app-developers app

patarchy said:
We need to secure several N7 that will be use by top management. We choose the N7 because no physical ports (unless the USB...). The back of the device will be glued, we will use a tailored version of Android (no google services at all) plus VPN for all data connection but we still get the physical access flaw issue.
Re: encryption
It does not cipher system file.
Sent from my Nexus 7 using xda app-developers app
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Hmm... In that case, you might just have to secure it physically. The only way to prevent the exploit you mentioned would be to develop a custom bootloader that doesn't allow fastboot without proper authentication. But that's unrealistic.
Sent from my Nexus 7 using Tapatalk HD

patarchy said:
We need to secure several N7 that will be use by top management. We choose the N7 because no physical ports (unless the USB...). The back of the device will be glued, we will use a tailored version of Android (no google services at all) plus VPN for all data connection but we still get the physical access flaw issue.
Re: encryption
It does not cipher system file.
Sent from my Nexus 7 using xda app-developers app
Click to expand...
Click to collapse
In that case you might look into well, a case with a lock to block the USB or maybe some other hardware hacks that impede the device from connecting to a computer.
A case with charge ports to the pogo pins that obstruct the USB might be an option.
But like what was said, i custom boot loader might be a better option, contact Google directly about how to block boot loader unlocks

Super glue the usb port and charge through pogo pins
Sent from my Nexus 7 using Tapatalk 2

Thanks a lot to all of you for your contributions.
We will super glue the USB port.
Sent from my Nexus 7 using xda app-developers app

Related

[DEV] Security risk for rooted or S-OFF users

Hello guys. I've became very interested lately about the posibility of locking my phone in case it was stolen. There are plenty of apps in the market that either allow you to remote lock or lock on SIM change. But a user who has some experience with adb or recovery will always be able to simply do a full wipe and flash a new ROM, thus rendering the locks useless. The easiest way is to put a pin when trying to acess the phone with ADB or a custom flashed recovery(S-OFF users). Personaly I do not know if tracking apps will still work in this case so I hope one of you will be able to provide a answer. Also if you have other suggestions of how security measures in this situations should be implemented please tell me.
Honestly there is no way to prevent people from using your phone if its stolen. Its always possible to do a factory reset to gain access to the device. The reason to password protect your phone is to prevent someone else from accessing the data on your phone, which would be erased by doing a factory reset.
Sent from my ADR6300
Runawaycoder said:
Honestly there is no way to prevent people from using your phone if its stolen. Its always possible to do a factory reset to gain access to the device. The reason to password protect your phone is to prevent someone else from accessing the data on your phone, which would be erased by doing a factory reset.
Sent from my ADR6300
Click to expand...
Click to collapse
Then factory reset must also be secured.
Xda app
TheRedDrake said:
Then factory reset must also be secured.
Xda app
Click to expand...
Click to collapse
But then there is no FailSafe for users who forget their password.
It really is an impossible situation - the best solution is either a hardware tracker or wiping data.
a33a said:
But then there is no FailSafe for users who forget their password.
It really is an impossible situation - the best solution is either a hardware tracker or wiping data.
Click to expand...
Click to collapse
Maybe a site where users can register and recover their PINs

why not to rename system app .bak (how I bricked my phone) - Resolved

Resolved: see post below.
Hi there, I'm really writing this hoping that maybe someone knows a fix for my problem and as a warning for why renaming system/apps with .bak is a silly idea when you can just do it via titanium or something similar.
About the device
Phone is a bell model, rooted but running the stock rom. I froze a bunch of apps with titantium (the smart way) but also added the .bak extension to some apps in the system/app folder.. I can't remember which ones but evidently important ones.
Everything was fine until today when an app I sideloaded caused my phone to go into a boot loop. I've been fighting with wakelock issues lately so I figured it wasn't a big deal to pop into the android recovery and do a factory restart. Problem is, some of the apps I added the .bak extension to are needed via the setup.
Problem I'm having
I can boot the phone fine and get to the blur setup screen which I can bypass as well. Problem is, once I skip the screen I immediately get a force close, and instead of taking me to the home screen, it goes back to the blur setup screen. I tried the keyboard shortcut bypass method which also works fine, but renders the phone useless since I can't access any menus, etc. It's just a black screen with the notification bar at the top. Horrah!
Long story short:
I can't enable usb debugging unless there is a way to sneak into the settings menu from the emergency call screen
Bell doesn't have a stock rom available
I can't re-root and fix my problem via adb because I can't turn on debug mode.
GAH!
Anyways, I'm pretty screwed. What are my choices?
I can return it to bell and hope they don't notice my giant gaff, flash an aftermarket rom and lose any warrenty I might have (I'm pretty toast now anyways) or buy a replacement phone.
Any thoughts would be greatly appreciated
- Kate
OMG
my heart had literally stopped beating for the past hour until I remember reading somewhere that you could text message a link to a replacement launcher hosted on dropbox.
OMG
Problem solved, phone is working.. I think.
Lesson for today kids: Do not mess with things you're not totally 100% sure about. Also, don't screw around with work phones. You need them to stay employed. Bricks don't keep you employed.
Flashing after market software shouldn't void your warrenty. I've sent in a few self bricked phones to bell.
Try early USB enumeration mode for ADB access
sent from my Atrix via XDA premium
marko! said:
Flashing after market software shouldn't void your warrenty. I've sent in a few self bricked phones to bell.
Try early USB enumeration mode for ADB access
sent from my Atrix via XDA premium
Click to expand...
Click to collapse
And I have sent 2 of my atrixs back to at&t both were unlocked and rooted
No questions asked not on extra doller spent I love insurance its worth 5 dollers a month to me + my phones were both bricked by apps in the android market
that's my story and I'm sticking to it!!!
Sent from my MB860 using xda premium
marko! said:
Flashing after market software shouldn't void your warrenty. I've sent in a few self bricked phones to bell.
Try early USB enumeration mode for ADB access
sent from my Atrix via XDA premium
Click to expand...
Click to collapse
Does that work even if usb debugging is off? If so, that's fantastic! I'll keep that in mind next time I'm in a horrible jam.
It wasn't market apps though that was my concern though... rather it was messing with system/apps and build.prop that had me concerned. Any wise tech would know that my problems weren't caused by some error on Motorola's part, but rather a silly girl who's breaking things from within.
Thanks though
I once told the **tech repairs specialist** that I bricked my phone installing a custom rom and got asked " what kind of customer was on the phone?"
Try and find NFHimselfs atrix mods apk it will help a lot
sent from my Atrix via XDA premium

Security: tablet encryption

For some reason I haven't ever put any thought into this option before. Do you use it? Does it slow the tablet down? I wanted an option to wipe data after a certain number of failed password attempts and it looks like the only way to do that (sort of) is to encrypt it and then you get an option to lose the encryption key after failed password attempts? Would love some opinions/suggestions. Thanks!
Sent from my Nexus 10 using Tapatalk HD
I'm really curious about this, too. Does anyone have their tablet encrypted? What are the practical effects it has on ROMing?
I believe encryption only slows it down on boot as it decrypt, once it's booted its fine. It just stops people ripping out the flash or making a dump and reading out your data.
Sent from my GT-I9300 using Tapatalk 2

[Q] Phone seems to be infected by a Trojan

A few days ago my phone arrived from Ebay. I set it up and all was OK until I put it on the wireless charger. Then I noted that someone started to remotely operate the phone - to switch applications and so on.
During the set-up I upgraded to 4.3 and installed stuff from big and known companies (Facebook, Microsoft, etc.), all from Google Play. I haven't installed anything else. Usually I am very careful with what I install on my devices because I've been developing software for long time and have some experience with security (although this is my first Android phone).
After I noted the issue I restored the phone to its factory settings, installed even less apps, however I experienced the same. The hacker even wrote something playful.
Could you pls tell me how to find out what is going on? Like how was it possible to put a Trojan that would survive an Android update and a factory restore? How to find the Trojan and so on. I later installed some antivirus/antimalware that reported that the phone is clean.
Thank you.
vkamenen said:
A few days ago my phone arrived from Ebay. I set it up and all was OK until I put it on the wireless charger. Then I noted that someone started to remotely operate the phone - to switch applications and so on.
During the set-up I upgraded to 4.3 and installed stuff from big and known companies (Facebook, Microsoft, etc.), all from Google Play. I haven't installed anything else. Usually I am very careful with what I install on my devices because I've been developing software for long time and have some experience with security (although this is my first Android phone).
After I noted the issue I restored the phone to its factory settings, installed even less apps, however I experienced the same. The hacker even wrote something playful.
Could you pls tell me how to find out what is going on? Like how was it possible to put a Trojan that would survive an Android update and a factory restore? How to find the Trojan and so on. I later installed some antivirus/antimalware that reported that the phone is clean.
Thank you.
Click to expand...
Click to collapse
Weird! What did the hacker wrote if I may ask?
I assume this is AndroRat, you can google on how to remove it (I wouldn't know).
Keep is updated!
Sent from my Nexus 4 using xda app-developers app
Factory restore doesn't touch tree system partition, so if the offending app was placed there resetting won't do anything.
Download the factory images from Google and flash them. It will revert you to complete stock
Sent from my Nexus 4 using xda app-developers app
no title
failly said:
Weird! What did the hacker wrote if I may ask?
Click to expand...
Click to collapse
He wrote something in the sort of "Flipped every turtle". I'll quote him after I manage to identify the hack (if I manage
Disconnect it from the net whilst you investigate to protect data
Sent from my Nexus 4 using xda app-developers app
as said above disconnect from wifi and remove your sim card. First thing i would do is use one of the toolkit to unlock or lock bootloader (it completely wipes everything); then do a factory reset. That should do the the trick. If the problem persist contact the police.
Locking our unlocking your bootloader doesn't wipe everything. It wipes userdata. It doesn't touch the system partition. As I said previously. The only surefire way to ensure a complete wipe is either to fully wipe all partitions and install a custom Rom.
Or if you wish to stay stock, download the nexus 4 stock images and flash them.
Doing this will erase all user data & all system data
It will then put stock files back on
Sent from my Nexus 4 using xda app-developers app
It seems like someone else is having the same behavior with their phone. Maybe it has something to do with the type of wireless charger.
Link: http://forum.xda-developers.com/showthread.php?t=2440115
It's probably just wireless charger bugging up the capacitive screen, try the stuff from above and when you flash a new image don't use the wireless charger for few days and see if it still happens.
Sent from my Nexus 4 using xda app-developers app

[Q] Device won't boot after failed root attempt

So i was trying to root my Nexus 7 for some of the many benefits that you get from rooting and half way through the process i messed up somewhere and now the device is completely bricked. I can't access bootloader or even start up the device at all. I have tried plugging it in to my PC and windows tells me that it isn't a Nexus 7 but instead it's called "QHSUSB_DLOAD" and i can't access it's internal storage at all.
I tried the many combinations of button holding and tried charging it, but still no response. I can't access it at all, it won't start, it's just gone. I can't use any of the features of my rooting toolkit either as it can't recognize the ABD. I was able to access bootloader for a while but when i decided to activate the Recovery mode, i saw the dead android and a warning sign above him.
So, Now it's just completely unresponsive and i can't plug it into a PC. I haven't even seen anything on the internet related to the QHUSB_DLOAD device that keeps appearing. I really need help with this. I can't even find anyone else with this problem, so i'm pretty worried... Also, I'm not used to installing and playing with mobile devices, so try to explain things in clear-ish english so i might actually understand some of the terms you use.
What method were you using to gain root? Was it a toolkit?
Sent from my ASUS Transformer Pad TF700T using xda app-developers app
duckredbeard said:
What method were you using to gain root? Was it a toolkit?
Sent from my ASUS Transformer Pad TF700T using xda app-developers app
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Click to collapse
Sorry for the late reply. I was trying to find my account for a while as I didn't save my login anywhere. As for a toolkit, yes, I was using the Wugfresh toolkit. Luckily for me, the problem seeming was an overnight fix. After I woke up, I was making breakfast and the tablet just decided to turn on next to me. I didn't even press the power button, which is kinda weird. Either way, Problem solved.
Sent from my now rooted Nexus 7. Awww Yea.
Thats the Android Magic.
SassMaster said:
Sorry for the late reply. I was trying to find my account for a while as I didn't save my login anywhere. As for a toolkit, yes, I was using the Wugfresh toolkit. Luckily for me, the problem seeming was an overnight fix. After I woke up, I was making breakfast and the tablet just decided to turn on next to me. I didn't even press the power button, which is kinda weird. Either way, Problem solved.
Sent from my now rooted Nexus 7. Awww Yea.
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