Issues cloning a Mifare Classic 1K token, original token now locked

[DiWiT]

Hi All,

I am trying to clone a “mifare classic 1k” token using the android “mifare classic tool” app, and I am having issues with this. Wondering if someone could help me?

This is the original token:

and this is the info I got when I read it using the app:

I read it using the app and saved the dump to my phone.

I bought these tags: https://es.aliexpress.com/item/1005006302595760.html

and then used the app: write tag > write dump (clone) > select dump > (select the saved dump from the original token) > tick all blocks (from 0 to 15) > OK

The tag was written successfully and it worked when I first tested it on the reader.

I then tried to use the original token on the reader and it did not work, and now the cloned one does not work either. I wrote the same token stored on my phone to a new blank tag and it does not work either.

Has my tag been banned / blocked on the system? May the entire system be locked now or is it just my tag?

Am I doing something wrong? Do I need to use these options in the app when writing to the new tag?

Thanks!

[Iceman]

Italiano… You ain’t ripping of a coffee machine are you now?

[xnzakg]

mmm, to me it seems like you may be (un?)lucky enough to have a more secure system than 99% of the access control systems most people encounter.

see something like:

Mifare 1k Clone stopped working - Flipper

This feels exactly like your access system is updating the card’s user memory space with data and checking for that data next time it’s used. It’s a shitty security mechanic but it works to block this very thing - makes clones of access cards impractical and at best only have a very short window of use… and even if used successfully the original cardholder will know something is up because their card won’t work anymore… But nobody knows about this security mechanism or cares. Anyway… if you wa…

can you check if all your tags have the same content?

[DiWiT]

I am not Italian, I guess you mean the Comelit brand is Italian. It is the access control system we have in the building I live in. They charge us €10 for every extra token we need, so I guessed it would be worth trying to clone them myself.

[DiWiT]

The thing is that I have no working tags now. The original stopped working after I used the cloned one, and the cloned one does not work after that either. So I only got the cloned one to work once, then used the original and looks like both were blocked on the system, which quickly blinks red-green constantly while the tag is on the reader.

I tried to write the dump of my original tag I had on my phone to a new tag but that does not work either.

What should I try at this stage?

Do those options that I highlight in my screenshot matter at all here?

Thanks!

[Equipter]

@DiWiT

What should I try at this stage

comelit are one of few staunchly anti-clone systems.

once the system recognised you presented a fob that did not carry an up-to date write it knows you cloned it and blacklisted it so not even the up to date one works.

my advice? go buy another fob from your building and don’t try and clone it. unless you are willing to constantly update both fobs after one of them has been used every single time, you aren’t gonna be cloning it.

[DiWiT]

I see, I guess it is good to know at least the system is secure. Will go buy another keyfob. Thanks all!