I’m with family for the holidays and thus haven’t been able to try with a proxmark, but using my flipper zero (the NFC Magic app > check magic tag > write) I tried to rewrite my flexUG4 from my apartment key to a website link to show off to my family. That write failed, but not before removing my original apartment key, and now I can’t seem to write anything to it, or even wipe it
Trying to write, wipe, or read the chip takes a long time as the flipper shows a loading bar for unlocking sectors 1-5, but only ever reports 2/10 keys found, and 1/5 sectors read, and afterwards, reads just say it’s “ISO14443-3A (unknown) UID: 11 22 33 44”
Is it bricked? Is there something I’m missing? Will a proxmark be able to save me where my flipper is failing (when I get home)?
What transponder is it you tried to write to it? I would be very surprised if it were bricked. Probably just failed to write the proper config. Do you have a proxmark?
The apartment key, which was on there for weeks beforehand, is a Mifare classic 1k. This problem began when I tried to switch it to an NTAG216. I do own a proxmark, but don’t have access to it until I get back from vacation on Sunday. I’ve tried the write, as well as reading and wiping, several times and they all fail
I have had some messed up UG4s that I have been able to reset with a proxmark. I haven’t used the flipper for this much. The proxmark script is pretty great.
I’ve basically only been using the NFC Magic app. I used NFC (basic) for the reads, but the writes and wipes are all through NFC Magic
It is the version that came with the Momentum firmware though, so I’m unsure if it’s version or if it’s entirely working right, there’s a few apps that have bugs with that firmware, but I did use it to write the apartment key weeks ago with no issues
I had read that too, which was part of deciding on this chip. So far though, the Proxmark hasn’t fared much better. Using
script run hf_mf_ultimatecard -u [my uid] -t 1
// this is correct as far as I know, I am trying to write a 4 byte uid Mifare Classic 1K
I get:
[+] executing lua C:\ProxSpace\pm3\proxmark3\client\luascripts/hf_mf_ultimatecard.lua
[+] args '-u [uid here] -t 1 -q 000408'
ERROR: iso14443a card select failed
ERROR: iso14443a card select failed
Setting: Ultimate Magic card to Mifare mini S20 4-byte
ERROR: iso14443a card select failed
[#] Warning: HF field is off
[#] Warning: HF field is off
ERROR: iso14443a card select failed
ERROR: iso14443a card select failed
Set max R/W block 13
ERROR: iso14443a card select failed
ERROR: iso14443a card select failed
ERROR: iso14443a card select failed
[+] finished hf_mf_ultimatecard
Which, safe to say, is not a resounding success.
I’ve tried with and without a proxmark booster, with varying hf tune values. With the booster, it hovers around 3400 mV before my UG4 is nearby, dropping to the low 2900mV area when its in position. Without the booster, it hovers nearer 15000, dropping down to 8000mV or so with the chip nearby
Oh, also just remembered and confirmed, running hw tune claims my HF antenna is only “marginal”. This is something I’m certainly not qualified to read or interpret, but here’s the full HF readout:
The only reason to just use the -u flag is that you are going to manually configure the rest of the necessary parameters. Doing just that will almost certainly give you a useless config.