Published: Tue, Jul 08, 25

Card (CUID)

Overview

This detailed tutorial walks you through using the Proxmark with IceMan firmware to read data from MIFARE Classic cards and clone it onto Magic Gen2 CUID cards. You’ll learn how to identify card types using IceMan-specific commands and outputs, dump card data, write new UIDs on compatible magic cards, troubleshoot common IceMan errors, and restore original dumps. Ideal for RFID researchers and enthusiasts working with IceMan’s advanced features.

Proxmark IceMan Firmware Tutorial

Dump and Clone MIFARE Classic and Magic Gen2 Cards

🚀 Tutorial #2 — Writing to Magic CUID Card (CARD B)

Now let’s clone that data onto a Magic Gen2 CUID card (CARD B).

This card supports writing block 0 (the UID block).

This card is a Magic Gen 2 / CUID type, supporting direct UID changes on block 0.

Step 1 — Connect Proxmark

Plug in your Proxmark navigate to the directory [/home/miscreant/iceman-proxmark3] and run:


root💀NullOrigin:~# ./pm3 -p /dev/ttyACM0

Step 2 — Check Card Info

  • Hold/Place CARD B near the antenna and run:

usb💀pm3--> hf mf info
usb💀pm3--> [=] --- ISO14443-a Information ---------------------
usb💀pm3--> [+]  UID: 79 12 3E 1E 
usb💀pm3--> [+] ATQA: 00 04
usb💀pm3--> [+]  SAK: 08 [2]
usb💀pm3--> [=] --- Keys Information
usb💀pm3--> [+] loaded 2 user keys
usb💀pm3--> [+] loaded 61 hardcoded keys
usb💀pm3--> [+] Sector 0 key A... FFFFFFFFFFFF
usb💀pm3--> [+] Sector 0 key B... FFFFFFFFFFFF
usb💀pm3--> [+] Sector 1 key A... FFFFFFFFFFFF
usb💀pm3--> [+] Block 0.... 79123E1E4B0804006263646566676869 | bcdefghi
usb💀pm3--> [=] --- Fingerprint
usb💀pm3--> [+] Fudan based card
usb💀pm3--> [=] --- Magic Tag Information
usb💀pm3--> [+] Magic capabilities... Gen 2 / CUID
usb💀pm3--> [=] --- PRNG Information
usb💀pm3--> [+] Prng....... weak

  

usb💀pm3--> hf mf wipe
usb💀pm3--> [=] Loaded keys matching MIFARE Classic 1K
usb💀pm3--> [=] Skipping sector 0 / block 0

usb💀pm3--> [=]  blk | 
usb💀pm3--> [=] -----+------------------------------------------------------------
usb💀pm3--> [=]    1 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]    2 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]    3 | FF FF FF FF FF FF FF 07 80 69 FF FF FF FF FF FF - key B ( ok )
usb💀pm3--> [=]    4 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]    5 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]    6 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]    7 | FF FF FF FF FF FF FF 07 80 69 FF FF FF FF FF FF - key B ( ok )
usb💀pm3--> [=]    8 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]    9 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   10 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   11 | FF FF FF FF FF FF FF 07 80 69 FF FF FF FF FF FF - key B ( ok )
usb💀pm3--> [=]   12 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   13 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   14 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   15 | FF FF FF FF FF FF FF 07 80 69 FF FF FF FF FF FF - key B ( ok )
usb💀pm3--> [=]   16 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   17 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   18 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   19 | FF FF FF FF FF FF FF 07 80 69 FF FF FF FF FF FF - key B ( ok )
usb💀pm3--> [=]   20 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   21 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   22 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   23 | FF FF FF FF FF FF FF 07 80 69 FF FF FF FF FF FF - key B ( ok )
usb💀pm3--> [=]   24 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   25 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   26 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   27 | FF FF FF FF FF FF FF 07 80 69 FF FF FF FF FF FF - key B ( ok )
usb💀pm3--> [=]   28 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   29 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   30 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   31 | FF FF FF FF FF FF FF 07 80 69 FF FF FF FF FF FF - key B ( ok )
usb💀pm3--> [=]   32 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   33 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   34 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   35 | FF FF FF FF FF FF FF 07 80 69 FF FF FF FF FF FF - key B ( ok )
usb💀pm3--> [=]   36 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   37 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   38 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   39 | FF FF FF FF FF FF FF 07 80 69 FF FF FF FF FF FF - key B ( ok )
usb💀pm3--> [=]   40 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   41 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   42 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   43 | FF FF FF FF FF FF FF 07 80 69 FF FF FF FF FF FF - key B ( ok )
usb💀pm3--> [=]   44 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   45 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   46 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   47 | FF FF FF FF FF FF FF 07 80 69 FF FF FF FF FF FF - key B ( ok )
usb💀pm3--> [=]   48 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   49 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   50 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   51 | FF FF FF FF FF FF FF 07 80 69 FF FF FF FF FF FF - key B ( ok )
usb💀pm3--> [=]   52 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   53 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   54 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   55 | FF FF FF FF FF FF FF 07 80 69 FF FF FF FF FF FF - key B ( ok )
usb💀pm3--> [=]   56 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   57 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   58 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   59 | FF FF FF FF FF FF FF 07 80 69 FF FF FF FF FF FF - key B ( ok )
usb💀pm3--> [=]   60 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   61 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   62 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - key B ( ok )
usb💀pm3--> [=]   63 | FF FF FF FF FF FF FF 07 80 69 FF FF FF FF FF FF - key B ( ok )

hf mf wipe command erases data blocks on a MIFARE Classic card by writing zeros or default values to each block except sector 0 block 0, which contains the UID and manufacturer data and is protected from wiping.

  • The tool reports each block wiped with data and confirms success with (ok).
  • Skipping sector 0 block 0 avoids corrupting the card UID.
  • This process resets all data blocks to empty/default states, effectively “cleaning” the card.
  • Useful for preparing cards for new data or resetting cloned cards.

usb💀pm3--> hf mf autopwn
usb💀pm3--> [!] ⚠️  no known key was supplied, key recovery might fail
usb💀pm3--> [+] loaded 5 user keys
usb💀pm3--> [+] loaded 61 hardcoded keys
usb💀pm3--> [=] Running strategy 1
usb💀pm3--> [+] target sector   0 key type A -- found valid key [ FFFFFFFFFFFF ] (used for nested / hardnested attack)
usb💀pm3--> [+] target sector   0 key type B -- found valid key [ FFFFFFFFFFFF ]
usb💀pm3--> [+] target sector   1 key type A -- found valid key [ FFFFFFFFFFFF ]
usb💀pm3--> [+] target sector   1 key type B -- found valid key [ FFFFFFFFFFFF ]
usb💀pm3--> [+] target sector   2 key type A -- found valid key [ FFFFFFFFFFFF ]
usb💀pm3--> [+] target sector   2 key type B -- found valid key [ FFFFFFFFFFFF ]
usb💀pm3--> [+] target sector   3 key type A -- found valid key [ FFFFFFFFFFFF ]
usb💀pm3--> [+] target sector   3 key type B -- found valid key [ FFFFFFFFFFFF ]
usb💀pm3--> [+] target sector   4 key type A -- found valid key [ FFFFFFFFFFFF ]
usb💀pm3--> [+] target sector   4 key type B -- found valid key [ FFFFFFFFFFFF ]
usb💀pm3--> [+] target sector   5 key type A -- found valid key [ FFFFFFFFFFFF ]
usb💀pm3--> [+] target sector   5 key type B -- found valid key [ FFFFFFFFFFFF ]
usb💀pm3--> [+] target sector   6 key type A -- found valid key [ FFFFFFFFFFFF ]
usb💀pm3--> [+] target sector   6 key type B -- found valid key [ FFFFFFFFFFFF ]
usb💀pm3--> [+] target sector   7 key type A -- found valid key [ FFFFFFFFFFFF ]
usb💀pm3--> [+] target sector   7 key type B -- found valid key [ FFFFFFFFFFFF ]
usb💀pm3--> [+] target sector   8 key type A -- found valid key [ FFFFFFFFFFFF ]
usb💀pm3--> [+] target sector   8 key type B -- found valid key [ FFFFFFFFFFFF ]
usb💀pm3--> [+] target sector   9 key type A -- found valid key [ FFFFFFFFFFFF ]
usb💀pm3--> [+] target sector   9 key type B -- found valid key [ FFFFFFFFFFFF ]
usb💀pm3--> [+] target sector  10 key type A -- found valid key [ FFFFFFFFFFFF ]
usb💀pm3--> [+] target sector  10 key type B -- found valid key [ FFFFFFFFFFFF ]
usb💀pm3--> [+] target sector  11 key type A -- found valid key [ FFFFFFFFFFFF ]
usb💀pm3--> [+] target sector  11 key type B -- found valid key [ FFFFFFFFFFFF ]
usb💀pm3--> [+] target sector  12 key type A -- found valid key [ FFFFFFFFFFFF ]
usb💀pm3--> [+] target sector  12 key type B -- found valid key [ FFFFFFFFFFFF ]
usb💀pm3--> [+] target sector  13 key type A -- found valid key [ FFFFFFFFFFFF ]
usb💀pm3--> [+] target sector  13 key type B -- found valid key [ FFFFFFFFFFFF ]
usb💀pm3--> [+] target sector  14 key type A -- found valid key [ FFFFFFFFFFFF ]
usb💀pm3--> [+] target sector  14 key type B -- found valid key [ FFFFFFFFFFFF ]
usb💀pm3--> [+] target sector  15 key type A -- found valid key [ FFFFFFFFFFFF ]
usb💀pm3--> [+] target sector  15 key type B -- found valid key [ FFFFFFFFFFFF ]

usb💀pm3--> [+] found keys:

usb💀pm3--> [+] -----+-----+--------------+---+--------------+----
usb💀pm3--> [+]  Sec | Blk | key A        |res| key B        |res
usb💀pm3--> [+] -----+-----+--------------+---+--------------+----
usb💀pm3--> [+]  000 | 003 | FFFFFFFFFFFF | D | FFFFFFFFFFFF | D 
usb💀pm3--> [+]  001 | 007 | FFFFFFFFFFFF | D | FFFFFFFFFFFF | D 
usb💀pm3--> [+]  002 | 011 | FFFFFFFFFFFF | D | FFFFFFFFFFFF | D 
usb💀pm3--> [+]  003 | 015 | FFFFFFFFFFFF | D | FFFFFFFFFFFF | D 
usb💀pm3--> [+]  004 | 019 | FFFFFFFFFFFF | D | FFFFFFFFFFFF | D 
usb💀pm3--> [+]  005 | 023 | FFFFFFFFFFFF | D | FFFFFFFFFFFF | D 
usb💀pm3--> [+]  006 | 027 | FFFFFFFFFFFF | D | FFFFFFFFFFFF | D 
usb💀pm3--> [+]  007 | 031 | FFFFFFFFFFFF | D | FFFFFFFFFFFF | D 
usb💀pm3--> [+]  008 | 035 | FFFFFFFFFFFF | D | FFFFFFFFFFFF | D 
usb💀pm3--> [+]  009 | 039 | FFFFFFFFFFFF | D | FFFFFFFFFFFF | D 
usb💀pm3--> [+]  010 | 043 | FFFFFFFFFFFF | D | FFFFFFFFFFFF | D 
usb💀pm3--> [+]  011 | 047 | FFFFFFFFFFFF | D | FFFFFFFFFFFF | D 
usb💀pm3--> [+]  012 | 051 | FFFFFFFFFFFF | D | FFFFFFFFFFFF | D 
usb💀pm3--> [+]  013 | 055 | FFFFFFFFFFFF | D | FFFFFFFFFFFF | D 
usb💀pm3--> [+]  014 | 059 | FFFFFFFFFFFF | D | FFFFFFFFFFFF | D 
usb💀pm3--> [+]  015 | 063 | FFFFFFFFFFFF | D | FFFFFFFFFFFF | D 
  

usb💀pm3--> hf mf dump
usb💀pm3--> [=] Using... hf-mf-79123E1E-key.bin
usb💀pm3--> [+] Loaded binary key file `/home/miscreant/hf-mf-79123E1E-key.bin`
usb💀pm3--> [=] Reading sector access bits...
usb💀pm3--> [=] .................
usb💀pm3--> [+] Finished reading sector access bits
usb💀pm3--> [=] Dumping all blocks from card...
usb💀pm3-->  🕓 Sector... 15 block... 3 ( ok )
usb💀pm3--> [+] Succeeded in dumping all blocks
usb💀pm3--> 
usb💀pm3--> [+] time: 9 seconds
usb💀pm3--> 
usb💀pm3--> [=] -----+-----+-------------------------------------------------+-----------------
usb💀pm3--> [=]  sec | blk | data                                            | ascii
usb💀pm3--> [=] -----+-----+-------------------------------------------------+-----------------
usb💀pm3--> [=]    0 |   0 | 79 12 3E 1E 4B 08 04 00 62 63 64 65 66 67 68 69 | y.>.K...bcdefghi
usb💀pm3--> [=]      |   1 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................
usb💀pm3--> [=]      |   2 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................
usb💀pm3--> [=]      |   3 | FF FF FF FF FF FF FF 07 80 69 FF FF FF FF FF FF | .........i......
usb💀pm3--> [=]    1 |   4 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................
usb💀pm3--> [=]      |   5 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................
usb💀pm3--> [=]      |   6 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................
usb💀pm3--> [=]      |   7 | FF FF FF FF FF FF FF 07 80 69 FF FF FF FF FF FF | .........i......
usb💀pm3--> [=]    2 |   8 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................
usb💀pm3--> [=]      |   9 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................
usb💀pm3--> [=]      |  10 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................
usb💀pm3--> [=]      |  11 | FF FF FF FF FF FF FF 07 80 69 FF FF FF FF FF FF | .........i......
usb💀pm3--> [=]    3 |  12 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................
usb💀pm3--> [=]      |  13 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................
usb💀pm3--> [=]      |  14 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................
usb💀pm3--> [=]      |  15 | FF FF FF FF FF FF FF 07 80 69 FF FF FF FF FF FF | .........i......
usb💀pm3--> [=]    4 |  16 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................
usb💀pm3--> [=]      |  17 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................
usb💀pm3--> [=]      |  18 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................
usb💀pm3--> [=]      |  19 | FF FF FF FF FF FF FF 07 80 69 FF FF FF FF FF FF | .........i......
usb💀pm3--> [=]    5 |  20 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................
usb💀pm3--> [=]      |  21 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................
usb💀pm3--> [=]      |  22 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................
usb💀pm3--> [=]      |  23 | FF FF FF FF FF FF FF 07 80 69 FF FF FF FF FF FF | .........i......
usb💀pm3--> [=]    6 |  24 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................
usb💀pm3--> [=]      |  25 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................
usb💀pm3--> [=]      |  26 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................
usb💀pm3--> [=]      |  27 | FF FF FF FF FF FF FF 07 80 69 FF FF FF FF FF FF | .........i......
usb💀pm3--> [=]    7 |  28 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................
usb💀pm3--> [=]      |  29 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................
usb💀pm3--> [=]      |  30 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................
usb💀pm3--> [=]      |  31 | FF FF FF FF FF FF FF 07 80 69 FF FF FF FF FF FF | .........i......
  

usb💀pm3--> hf mf wrbl --blk 0 -d E362411FDF0804006263646566676869
usb💀pm3--> [=] Targeting Sector 0 / Block 0 - Manufacturer block
usb💀pm3--> [=] Read the helptext for details before writing to this block
usb💀pm3--> [=] You must use param `--force` to write to this block

Command


root💀NullOrigin:~# hf mf wrbl --blk 0 -d E362411FDF0804006263646566676869

Detailed Breakdown: What is going on here?

Command

This command tells the Proxmark3 tool to write a block (wrbl = write block) to a MIFARE Classic card, specifically targeting block 0 (--blk 0) with the given data (-d E362411FDF0804006263646566676869).

What is Block 0?

Block 0 in MIFARE Classic cards is special because it contains the manufacturer data, which includes the card’s UID (Unique Identifier) and other factory-programmed information.
This block is generally read-only or protected to prevent tampering because the UID is supposed to be unique and unchangeable by design.

Output Explanation

  • [=] Targeting Sector 0 / Block 0 - Manufacturer block
    The Proxmark3 recognizes block 0 belongs to sector 0 and is the manufacturer block containing the UID and other critical data.

  • [=] Read the helptext for details before writing to this block
    This is a cautionary message reminding you that writing to this block is sensitive and potentially risky. Improper writes can damage the card or render it unusable.

  • [=] You must use param '--force' to write to this block
    To prevent accidental writes, the tool requires an explicit confirmation flag --force to allow you to write to this protected block.
    This safety measure ensures the user is aware of the risks and intends to override default protections.

Why is this important?

Manufacturer Block Protection

The UID stored in block 0 is essential for the card’s identity and security functions. Changing it can cause the card to malfunction or be rejected by systems expecting that UID.

Legality and Ethics

Modifying manufacturer blocks may be illegal or unethical depending on jurisdiction and use case because it can be used to clone or spoof cards.

Tool Safety

Proxmark3 protects the user from unintentional writes to this critical block by requiring the --force flag. This encourages the user to carefully review the risks before proceeding.


usb💀pm3--> hf mf wrbl --blk 0 -d E362411FDF0804006263646566676869 --force
usb💀pm3--> [=] Writing block no 0, key type:A - FFFFFFFFFFFF
usb💀pm3--> [=] data: E3 62 41 1F DF 08 04 00 62 63 64 65 66 67 68 69 
usb💀pm3--> [+] Write ( ok )

Forcing the Write


root💀NullOrigin:~# hf mf wrbl --blk 0 -d E362411FDF0804006263646566676869 --force
  • The –force parameter overrides safety checks, allowing writing to protected blocks (like the manufacturer block).

    • Output messages explained:

      [=] Writing block no 0, key type:A - FFFFFFFFFFFF
The card was accessed using the default key FFFFFFFFFFFF for authentication.

[=] data: E3 62 41 1F DF 08 04 00 62 63 64 65 66 67 68 69
The exact 16 bytes of data being written to block 0.
[+] Write ( ok )
  
The write operation completed successfully.


usb💀pm3--> hf mf info
usb💀pm3--> [=] --- ISO14443-a Information ---------------------
usb💀pm3--> [+]  UID: E3 62 41 1F 
usb💀pm3--> [+] ATQA: 00 04
usb💀pm3--> [+]  SAK: 08 [2]
usb💀pm3--> [=] --- Keys Information
usb💀pm3--> [+] loaded 2 user keys
usb💀pm3--> [+] loaded 61 hardcoded keys
usb💀pm3--> [+] Sector 0 key A... FFFFFFFFFFFF
usb💀pm3--> [+] Sector 0 key B... FFFFFFFFFFFF
usb💀pm3--> [+] Sector 1 key A... FFFFFFFFFFFF
usb💀pm3--> [+] Block 0.... E362411FDF0804006263646566676869 | bcdefghi
usb💀pm3--> [=] --- Fingerprint
usb💀pm3--> [+] Fudan based card
usb💀pm3--> [=] --- Magic Tag Information
usb💀pm3--> [+] Magic capabilities... Gen 2 / CUID
usb💀pm3--> [=] --- PRNG Information
usb💀pm3--> [+] Prng....... weak

_______________________________________________________

⚠️ Legal Disclaimer

Changing or cloning RFID cards may be illegal if used for unauthorized access. Only experiment on your own cards or with permission.