Is it possible to update/modify IMSI number of a SIM card?

Question

Is it possible to edit an existing IMSI of a SIM card by overwriting the EF_IMSI file system? If yes then can we do this by using AT Commands or how can we do it?

Thank you very much for your help

Solution

Yes you can change Data of EF imsi Just run the following commands

a0 a4 00 00 02 3f00 -> Select MF

a0 a4 00 00 02 7f20 -> Select DF_GSM

a0 a4 00 00 02 6f07 ->Select EF_IMSI

a0 d6 00 00 09 <9 bytes of MSI data> -> Update IMSI

These commands are ISO 7816 commands.To know more about commands and file structure of SIM.Please refer link,For commands goto page41. To run these commands you can use link

Comments

[user1725145]

Hi @AnuragSharma, can you please explain this answer a bit more? What interface are you using? is there a spec or is it proprietary? what privileges/test equipment do you need to use these commands? (I'm not being a rules bore by the way - I'm interested)

[Anurag Sharma]

These commands are ISO 7816 commands.To know more about commands and file structure of SIM.Please refer link,For commands goto page41. To run these commands you can use link

[user1725145]

Thanks for the info. +1. It would be good Stack Overflow style if you would add this comment into your answer, by the way.

[Anurag Sharma]

Thanks @S List...already updated my answer i will keep this practise for my future updates.

[David]

In addition: directly after SELECTing EF_IMSI, send GET RESPONSE command to get file information then parse it according to 3GPP TS 11.11. If the access condition to Update operation is not ALWays, then you need to do successful verification using VERIFY command before sending the UPDATE BINARY command. On the standard specification, it is protected by ADM key, which mean only several people can update this file.

[Minh Nguyen]

Indeed David's answer is absolutely right. And the above commands are APDU commands, not AT Commands.