Serial number Change on MifareClassic

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1

Hi Friends!

I am really happy cause I bought a proxmark3 2 days and the learning has been soo sick.

Long story short, I own a lundryShop and I have this fidelity cards that money can be allocated to the card for usage.

Now, with the proxmark 3 I was able to successfully clone the card onto a blank-card and test it out in the shop and it works great!

Now, my task is to find a way to change the serial-number that the card comes with and change the serialNumbers on the clones that way I am able to offer this service to my clients.

I have followed two tutorials to achieve this:

They are:

I was able to run an autopwn script on the card with efaultKeys and it worked hf mf autopwn -f mfc_default_keys.

Went from 14 missing blocks to
Screenshot 2024-09-02 at 15.25.51

To getting all 16 blocks
Screenshot 2024-09-02 at 15.27.36

I was able to notice that the serialNumber is not represented within any of he 16 blocks (neither a or b) within the card and this is where my mind starts to wonder.

Is it possible to assign a new serialNumber to each card, if so hw can this be achieved?

THANKS to the whole team and ICEMAN!

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2

those are not the data blocks, those are the sector keys. look at the generated dump.bin file that is output by autopwn. not the key.bin files

MFC 1K Datasheet

on non magic mifare classic you cannot change the serial number /UID . it is burned in.

for magic cards, to change the UID the method you use is dependent on the magic card you buy

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3

So, if you own the shop, why do you need to clone closed loop stored value cards?

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4

Hey Hey Amal!

So the issue is the following:

I own the shop yet I am vendorLocked in with a really old-school payment machine that has this card-system applied to it.

Now, the fun part they charge over 4$ for each new card, so it a good side-business they have going on. Nevertheless,

I was able to do it perfectly with this command:

hf mf csetuid -u [00000001]
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5

Dude this is sick! thanks so much for this PDF!

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UPDATE!!

Hello to all!

I was able to find a good article detailing how to approach the change of Serial Number on these cards.

This article provides an example command from the mf mifare set of commands.

Here is the command:

hf mf csetuid -u [00000001]

This approach does the work, here is a quick snapshot from my terminal!

Screenshot 2024-09-03 at 10.25.57

Learning everyday a bit more!

Thanks DT Team!

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