If default keys fail, run an offline cracking tool. For example, using a Proxmark3, you would run the auto-pwn command. The software will attempt a DarkSide attack to get a foothold, followed by a Nested or Hardnested attack to extract the keys for all 16 or 40 sectors. Step 3: Dump the Card Data
If the sector trailer (Sector 0) is destroyed, you may need a "Magic Card" (Gen1 or Gen2) to rewrite the UID and restore the sector structure. Handling "Hardened" or "Locked" Cards
: The app comes with standard default keys (e.g., FFFFFFFFFFFF ). You can create custom key files if you have specific keys for your tag . 2. Reading and Recovering Data mifare classic card recovery tool
Once all 16 keys are recovered, you dump the binary: hf mf dump -k dumpkeys.bin -o card_dump.bin You now have a binary recovery file. You can write this to a new "Magic Gen 1A" or "Gen 2" card.
The Proxmark3 is the gold standard for RFID research and data recovery. It features a powerful FPGA and microcontroller capable of executing high-speed cryptographic attacks directly on the device. It supports the nested, hardnested, and darkside attacks natively through its command-line interface. 2. Flipper Zero If default keys fail, run an offline cracking tool
Safety Note: Only perform data recovery, backup, or auditing on RFID assets that you legally own or have explicit authorization to test. Phase 1: The Dictionary Attack
: You should only recover data from cards that you own or have explicit, written authorization to audit. Step 3: Dump the Card Data If the
MIFARE Classic cards are divided into sectors, each protected by two keys (Key A and Key B) .
This practical guide assumes you have a Proxmark3 or ACR122U reader connected to a Linux machine (Kali Linux recommended).
Reading and writing sector data, cracking keys (if default keys are present), and identifying corrupted sectors.