Hi guys,
First post, so, firstly, hello! I've been using this website for a while,
I have a question that need to help.
I'm using S620 n I have installed App F-Secure Mobile Security to Anti-theft only.(this app will send a private message to me when SIM changed.)
To enable Remote Lock Function, I must set my S620 locked.
However if the device locked, when U start your device, it will require to type your password. How must I do to disable this func. when starts. Because when my device is stolen, if it locked, the theft can hard reset all.
It want to be a Remote Control and a Remote Lock that the theft don't know!
I tried to search and found "Device Lock.exe" and "Device Lock.mui" files in Windows Folder but I can't open Device Lock.mui
Thanks!
While unlocking the bootloader on a Galaxy Nexus unleashes the full potential of the bootloader, it also poses a security risk. Even with your lockscreen protected with a pattern/PIN/password, not having flashed a custom recovery, having an anti-theft app installed (maybe even converted/installed as a system app) your phone's data is easily accessible for a knowledgeable thief.
All the thief needs to do is reboot into the bootloader and boot or flash a custom recovery such as ClockWorkMod or TWRP. It's then possible to boot into recovery and use ADB commands to gain access to the phone's data on the internal memory (unless you have it encrypted) and copy/remove files at will.
Granted, the risk seems low. The thief would not only require knowledge of fastboot, he would have to turn off the phone before you have issued a wipe command using an anti-theft app. You could of course flash back the stock recovery & relock the bootloader after being done with flashing stuff, but that would require you to unlock it again if needed which will erase your userdata.
There are two ways to tackle this security risk AND retain unlocked bootloader functionality without losing userdata.
1) Encrypt your phone using Android's built-in encryption feature
Advantages:
- you can leave your bootloader unlocked & leave a custom recovery installed without risk of exposing your data.
Disadvantages:
- unless the custom recovery can decrypt your phone, you cannot use all of its features.
- when decryption fails, you cannot access your phone and need to do a factory reset from recovery. Users have reported not being able to decrypt after applying OTA updates.
- the encryption process is irreversible. The only way to return to an unencrypted phone is to perform a factory data reset which erases all your data.
2) Unlock & relock the bootloader from Android OS
Prerequisites:
- root access
- an app that can unlock/relock the bootloader at will such as BootUnlocker
Steps
Root your device using one of the many guides out there (recommended guide). Install BootUnlocker. Reflash stock recovery and lock the bootloader. Whenever you need an unlocked bootloader again, simply use Bootlocker to unlock it (this won't wipe userdata). When done, relock.
Advantages:
- doesn't require encryption (for those who do not wish to use it).
Disadvantages:
- relies on third-party apps.
- method will not work if you lose root access for whatever reason.
- method will not work when you cannot boot into Android for whatever reason.
USB debugging
Strictly not related to the bootloader, but for maximum security disable USB debugging when not required. Having it enabled allows the execution of ADB commands even if the lockscreen is still locked. Myself, I use Tasker in combination with Secure Settings to automatically enable USB debugging when my device is connected to my home WiFi access point but disabled if not connected.
The following video demonstrates what a knowledgeable thief can do with your phone when you have USB debugging enabled by default: http://www.youtube.com/watch?v=ah7DWawLax8&t=7m0s
More info: recently, an exploit has been discovered that will enable gaining root without going through the 'traditional' process of unlocking the bootloader & flashing a custom recovery in order to flash Superuser or SuperSU packages. See this post for a guide.
Play store devices
Devices bought directly from Google's Play Store apparently do NOT wipe userdata after fastboot oem unlock. So for these devices, method number 2 does not add any security. For more info, read this thread: http://forum.xda-developers.com/showthread.php?t=1650830
Very well written!!
One thing you may want to tie in to your explanation is the effect of having USB Debugging enabled - it's easy to gain root (and subsequently unlock your bootloader) with it enabled, even with a locked bootloader.
Sent from my Galaxy Nexus using Tapatalk 2
Added some information regarding USB debugging. Thanks for the tip efrant.
Good read:good:
Do you have to be on stock rom to lock the bootloader ?
Oscuras said:
Do you have to be on stock rom to lock the bootloader ?
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Click to collapse
Nope.
Sent from my Galaxy Nexus using Tapatalk 2
Thanks for this :good:
Trying to wrap my head around this with regards to anti theft protection etc.
Currently have an unlocked bootloader, custom rom, and root. If I have something like Cerberus or Avast running (both claim to work as system apps so will not be deleted via hard reset), have debugging unchecked and a pin lock at screen on - if I lock bootloader now, how secure am I to data theft?
Presumably, with debug disabled, fastboot from pc command prompt to unlock bootloader will not work? Can ODIN be used to flash a new ROM and if so my system apps (and thus the security apps) will be wiped, rendering the whole thing useless?
Thanks
Guiding.God said:
Thanks for this :good:
Trying to wrap my head around this with regards to anti theft protection etc.
Currently have an unlocked bootloader, custom rom, and root. If I have something like Cerberus or Avast running (both claim to work as system apps so will not be deleted via hard reset), have debugging unchecked and a pin lock at screen on - if I lock bootloader now, how secure am I to data theft?
Presumably, with debug disabled, fastboot from pc command prompt to unlock bootloader will not work? Can ODIN be used to flash a new ROM and if so my system apps (and thus the security apps) will be wiped, rendering the whole thing useless?
Thanks
Click to expand...
Click to collapse
If you have the stock recovery (custom will allow adb), your personal data is as secure as it can be. Of course, you cannot stop anybody from booting into your bootloader and run fastboot oem unlock OR use Odin to flash your device. However, doing so will effectively wipe your device so your personal data cannot be accessed.
I would more worry about my phone then data because I have nothing important on it...
Sent from my Galaxy Nexus using xda premium
Petrovski80 said:
If you have the stock recovery (custom will allow adb), your personal data is as secure as it can be. Of course, you cannot stop anybody from booting into your bootloader and run fastboot oem unlock OR use Odin to flash your device. However, doing so will effectively wipe your device so your personal data cannot be accessed.
Click to expand...
Click to collapse
qtwrk said:
I would more worry about my phone then data because I have nothing important on it...
Sent from my Galaxy Nexus using xda premium
Click to expand...
Click to collapse
Thanks for the clarification.
And I worry more about the work related data, the phone itself is insured
This is important info, and a lot of folks probably don't realize how open they are. This should be stickied or better yet included in the stickied thread where the bootloader unlock instructions are. Thanks for the post.
Great info. One question, I use Titanium Backup automated nightly to backup data and new apps, and it requires USB Debugging on.
I suppose I could use Secure Settings to turn USB Debugging on and off, but that means an opening is available once a day for a few minutes. Thoughts?
Pkt_Lnt said:
Great info. One question, I use Titanium Backup automated nightly to backup data and new apps, and it requires USB Debugging on.
I suppose I could use Secure Settings to turn USB Debugging on and off, but that means an opening is available once a day for a few minutes. Thoughts?
Click to expand...
Click to collapse
You could do as I do: use secure settings in combination with tasker so USB debugging will only be enabled when connected to your home Wifi. It will allow your nightly TiB backups, and I assume the 'ADB opening' is not an issue when at home (not many thieves there I hope).
Petrovski80 said:
You could do as I do: use secure settings in combination with tasker so USB debugging will only be enabled when connected to your home Wifi. It will allow your nightly TiB backups, and I assume the 'ADB opening' is not an issue when at home (not many thieves there I hope).
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Click to collapse
I downloaded Secure Settings to check it, and it will work. I have AutomateIT Pro and it does not support plug-ins. I have been finding more tasks that it seems only Tasker can perform, I guess it is time to get it. Thank you.
Petrovski80 said:
You could do as I do: use secure settings in combination with tasker so USB debugging will only be enabled when connected to your home Wifi. It will allow your nightly TiB backups, and I assume the 'ADB opening' is not an issue when at home (not many thieves there I hope).
Click to expand...
Click to collapse
Great idea.
Petrovski80 said:
You could do as I do: use secure settings in combination with tasker so USB debugging will only be enabled when connected to your home Wifi. It will allow your nightly TiB backups, and I assume the 'ADB opening' is not an issue when at home (not many thieves there I hope).
Click to expand...
Click to collapse
A Jasager router could exploit this if you have WiFi enabled in public. When WiFi is enabled and not connected to a network, every 'x' period of time (depending upon your wifi.supplicant_scan_interval setting in your build.prop) your phone will send out a packet saying "hey, is xyz network around?". It will do that for every network that you have saved settings for.
Under normal circumstances, you get no reply when away from your home router and the phone just waits the interval to try again. A Jasager ("yes man" in German) router waits for a device to send out those packets and simply responds "yep, that's me!". Under this circumstance, your phone would authenticate to their router and think it's on your home network, triggering any applicable Tasker options.
This is one of the reasons that I do not have WiFi enabled unless I actively want to be connected to a router in the area.
Also, I have USB Debugging disabled and my TiBu backups run perfectly fine according to schedule.
I am not a paranoid worry wart so the risk are more than worth it for me. There's nothing on here that I would care if some one got a hold of anyway.
Sent from my Galaxy Nexus using xda premium
Cilraaz said:
A Jasager router could exploit this if you have WiFi enabled in public. When WiFi is enabled and not connected to a network, every 'x' period of time (depending upon your wifi.supplicant_scan_interval setting in your build.prop) your phone will send out a packet saying "hey, is xyz network around?". It will do that for every network that you have saved settings for.
Under normal circumstances, you get no reply when away from your home router and the phone just waits the interval to try again. A Jasager ("yes man" in German) router waits for a device to send out those packets and simply responds "yep, that's me!". Under this circumstance, your phone would authenticate to their router and think it's on your home network, triggering any applicable Tasker options.
This is one of the reasons that I do not have WiFi enabled unless I actively want to be connected to a router in the area.
Also, I have USB Debugging disabled and my TiBu backups run perfectly fine according to schedule.
Click to expand...
Click to collapse
Maybe. Tasker checks both the SSID and the MAC address of my router before it returns 'wifi connected' as true and enables USB debugging. Sure, MAC addresses are easy to spoof, but I don't think the MAC address is part of the broadcast packet (I haven't checked) because that's simply a value stored by Tasker itself.
And even if it is, the combination of a lost/stolen GNEX and a thief who modded their router with jasager firmware + knows ADB is too unlikely for me to worry about it. But indeed, for maximum security it's best not to automate enabling of USB debugging.
Petrovski80 said:
Maybe. Tasker checks both the SSID and the MAC address of my router before it returns 'wifi connected' as true and enables USB debugging. Sure, MAC addresses are easy to spoof, but I don't think the MAC address is part of the broadcast packet (I haven't checked) because that's simply a value stored by Tasker itself.
And even if it is, the combination of a lost/stolen GNEX and a thief who modded their router with jasager firmware + knows ADB is too unlikely for me to worry about it. But indeed, for maximum security it's best not to automate enabling of USB debugging.
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Click to collapse
The MAC check would almost certainly keep you safe.
It's interesting stumbling across this thread after having just seen a podcast episode about Android hacking. If anyone is interested, check out Hak5. One of their recent episodes is about Android hacking via ADB, specifically something called P2PADB that was created for quick device-to-device ADB access. It was fairly amazing the things this person could do to a phone that has USB Debugging enabled.
Cilraaz said:
The MAC check would almost certainly keep you safe.
It's interesting stumbling across this thread after having just seen a podcast episode about Android hacking. If anyone is interested, check out Hak5. One of their recent episodes is about Android hacking via ADB, specifically something called P2PADB that was created for quick device-to-device ADB access. It was fairly amazing the things this person could do to a phone that has USB Debugging enabled.
Click to expand...
Click to collapse
Watching the video right now. Personally, I find it a gaping security hole that the ADB interface is accessible through a locked lockscreen.
For anyone interested in the vid: the ADB part starts at 7:00.
Edit: amazing video. It really proves what a knowledgeable thief can do when you have USB debugging enabled, especially when combined with root access (don't we all?). I'm going to add the video to my post. Thanks for the info Cilraaz!
Hi friends, Yesterday i just tried to change my lock pin on my M9 (running latest naugat)but somehow i forgot it after setting it up.(stupid me). Then i tried to use android device manager to clear the pin .After signing in into manager,i could see my device and it presented couple of options.One of then was LOCK.After entering into Lock, Android device manager prompted me to enter temporary password and i entered it.But it didn't work.
At one point i thought i was going to loose all of my pics,data.But fortunately somehow i managed to enter the right pin after couple of tries.
So can't android manager be used to clear the pin on M9?I would like to know if in future someone gets into this kind of problem.Thanks
Android manager is basically an emergency lock out security app which gives you the ability to remotely lock the device and destroy the private data on it before it is compromised, effectively making the device 'useless' until it is flashed. It doesn't protect the phone except for reporting its location if connected to the Internet, it protects only the data on the phone. Nothing more.
Beamed in by telepathy.
shivadow said:
Android manager is basically an emergency lock out security app which gives you the ability to remotely lock the device and destroy the private data on it before it is compromised, effectively making the device 'useless' until it is flashed. It doesn't protect the phone except for reporting its location if connected to the Internet, it protects only the data on the phone. Nothing more.
Beamed in by telepathy.
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Click to collapse
Thanks for the reply.So is there any way to recover phone via google account login without loosing data or pictures?