Undetectable MIFARE Classic® Compatible 1K - One Time Write UID

INTRODUCTION

Need to make perfect, undetectable of MIFARE Classic® 1K Cards ?

Many access control systems / RFID readers are now able to detect "Chinese Magic" tags by sending the "Unlock Command" (0x40 / 0x43). If the badge replies, it is flagged as an imposter / clone and rejected.

These "Gen2a" badges allow the UID to be set one time only - and after that - the tag never responds to magic commands. This allows you to make undetectable, perfect clones.

Once the UID has been set, the tag acts as a normal card. You can change the data of the card as many times as required - we've tested up to 10,000 read/write cycles.

Remember: This badge's UID can only be set one time.

These tags are red and in key ring form for convenience.

Hands on: See the card in action

The MIFARE Classic® Compatible 1K UID One-Time-Write can be used with several tools:

LibNFC - change UID

To update the UID of the badge, simply write the dump contents to the badge.

nfc-mfclassic w a u /tmp/1K.dmp

Proxmark - change UID

To update the UID of the badge, simply write the dump contents to the badge. When using wrbl - you are directly modifying the card's configuration. Ensure that all data is correct including BCC - otherwise you will brick your card.

hf mf wrbl --blk 0 -k FFFFFFFFFFFF -d 11223344440804006263646566676869 # Where 11223344 is the UID, 08 is the BCC

Unbricking

"Soft-bricking" refers to when a magic card has been configured in a way that prevents it from being detected. Ways of soft-bricking tags include:

• Incorrect BCC
• Incorrect SAK
• Incorrect ATQA
• Incorrect ATS
• Incorrect ACL (Access Control) Values

With Proxmark / iCopy-X

hf 14a config --atqa force --bcc ignore --cl2 skip --rats skip

# for 1k
hf mf wrbl --blk 0 -k FFFFFFFFFFFF -d 11223344440804006263646566676869 --force

hf 14a config --std
hf 14a reader

Via external reader/writer and MTOOLS

Select the "UID Changer" function in MTools, select "bricked" and run the task

IMPORTANT:

Lab401 cannot provide refunds under any circumstances for cards that were 'bricked' due to incorrect configurations.