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I read that mobile network providers can block IMEI numbers from most networks but I also read that criminals can change these IMEI numbers in order to regain access to a network. How is this done and what can I do to protect myself from it?

schroeder
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Joe
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    "_what can I do to protect myself from it?_" I may be missing something, but what do you feel you need protecting from? In what way are you "_in danger_" from a criminal who somehow manages to regain access to the mobile network (especially given they could just get a new phone)? – TripeHound Mar 13 '20 at 13:55

1 Answers1

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criminals can change these IMEI numbers in order to regain access to a network.

Not only criminals, changing IMEI is easy even without root access, there are plethora of apps that can do just that.

How is this done and what can I do to protect myself from it?

For most devices, IMEI is stored in EEPROM, simply raising a voltage from normal working one will allow you to change whatever is stored on it.

You mostly can't do anything to protect only IMEI. Hardware limitations. However, you can for example encrypt your phone internal storage, set a startup code, enable device locator and so on. This will make it harder for criminal who stole your device to actually profit from it.

Unfortunately, not all phone models support that (startup encryption)

Rashad Novruzov
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  • Yeah i know about startup encryption i have seen some Samsung S models that support it ( S8/S9 are two that i know of ) And i read something about it being stored in a EFS on the device and if you root the device and then somehow corrupt the file and restore from a backup of another device then you can change the IMEI how true and possible is this? – Joe Mar 13 '20 at 18:19
  • One more question let's say a criminal takes my phone and doesn't use it for anything but just copies my IEMI number to a new device will this render my device useless on that network since there will be two copies or what? Sorry for not making very much sense just new to possible cell phone scams – Joe Mar 13 '20 at 18:21
  • And what do you mean by raising the voltage from normal working how does that change the IMEI? And does a criminal have to use a legitimate IMEI number or can they just generate a random one? These apps you mention how do they change the number? – Joe Mar 13 '20 at 18:36
  • All right - corrupting and restoring device from a backup - not sure about it, probably related to some models and firmware versions. Copy IMEI and use it on another device - The one that was registered first to a number will have a prevalence. EEPROM memory to be able to overwrite you need to fluctuate voltage (raise it) to wipe and overwrite. Just google EEPROM, your laptop's bios works the same for example. – Rashad Novruzov Mar 13 '20 at 18:45
  • Refer to this: https://en.wikipedia.org/wiki/International_Mobile_Equipment_Identity For IMEI generation procedure: https://www.gsma.com/newsroom/wp-content/uploads//TS.06-v16.0.pdf – Rashad Novruzov Mar 13 '20 at 18:48
  • From what i read the process is you corrupt the EFS on a rooted phone and then you make a backup of the IMEI of another phone and afterwards you copy that backup to your computer and then to the other phone afterwards using a EFS restore tool you can restore the EFS to the target phone making the IMEI register as another – Joe Mar 13 '20 at 18:50
  • Also what about a IMEI that is on a phone that isn't in use on any cellular networks anymore could a attacker use that for a stolen phone? – Joe Mar 13 '20 at 18:52
  • Generally, rooting a phone is against security guidelines. If IMEI is spoofed that is not tied to a phone number, the one that will be tied will have prevalence. There are however ways to circumvent if you will become the owner of a phone with a legitimate IMEI that was spoofed by another. You will need to talk to a vendor and gsm provider. – Rashad Novruzov Mar 13 '20 at 19:00