Edit arcade machine NFC card

NFC
#1

Hello,
I have read an NFC card from arcade games, I am trying to edit the NFC file:

Filetype: Flipper NFC device
Version: 3
# Nfc device type can be UID, Mifare Ultralight, Mifare Classic or ISO15693
Device type: Mifare Classic
# UID is common for all formats
UID: CE 8D DF 7C
# ISO14443 specific fields
ATQA: 00 04
SAK: 08
# Mifare Classic specific data
Mifare Classic type: 1K
Data format version: 2
# Mifare Classic blocks, '??' means unknown data
Block 0: CE 8D DF 7C E0 08 04 00 62 63 64 65 66 67 68 69
Block 1: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Block 2: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Block 3: FF FF FF FF FF FF FF 07 80 69 FF FF FF FF FF FF
Block 4: 36 36 32 37 30 33 30 30 30 30 30 30 31 31 31 37
Block 5: 36 34 36 36 31 37 36 30 33 36 33 32 36 37 38 33
Block 6: 30 39 35 35 35 34 39 38 00 00 00 00 00 00 00 00
Block 7: FF FF FF FF FF FF FF 07 80 69 FF FF FF FF FF FF

The rest of the blocks are repeated in groups of 4 blocks.

I have only managed to locate the pairs in hexadecimal that correspond to the card number

Block 4: 36 36 32 37 **[30 33 30 30 30 30 30 30 31 31 31 37**
**Block 5: 36 34 36 36]**

Can you help me understand where the balance can be located?

Is it possible that I can edit the card number and get a new one with the same balance?

Regards

2 Likes
#2

What you are trying to do is illegal and i shouldn’t be helping with this but ,

Read the card with some balance, for example 5 credits,
Spend one credit and read the card again with 4 credits,
Read again with 3 and so on … you will see on the dumps what portions of the data is changing as you spend credits.

Try to use the option to write to initial card the first dump (the one with 5 credits) after you spend all the money … does it restore the balance ?

Do not update from initial card to flipper dump, keep making different dumps for different amonts of $$$

The $$$ can be either saved on the pages of the card as data or on the system and linked to the card only by UID for example. If you write to initial card a dump for example of 5 credits when the card have 0 credits if the credits don’t go up to 5 then the credit is saved outside the card and it’s game over !!!

If you write a dump of 5 credits to an empty card and it gets 5 credits again then the $$$$ is saved on the card and you are good to go …

If the $$$ is on the system/network/machine and not on the card you could try to guess valid UIDs for other cards with $$$$ and use those credits but original legal owners of those cards would have their credits consumed by you ,

5 Likes
#3

To add an additional layer… remember if it’s a server-side accounting system, most of those “arcades” have decent security camera systems. If they see a string of fraudulent attempts, all it’ll take is a look at timestamps on the video recordings to see you’re the one doing it. Then it’s another form of “game over”. :wink:

1 Like
#4

What are you trying to achieve with this ???

#5

What are you trying to do on arcade machine :thinking:

#6

afaik you can’t edit credits because they are stored on a server and not on the card itself. The card contains information which verifies that it is you registered on the server and the server responds with info that allows you to game or not.

#7

Now wouldn’t that be embarrassing to tell your cellmate that you’re in for stealing arcade “game play” :joy:

Your cellmate will have fun playing games with you :poop: