mask attack blockchain wallet
#1
We have attempted to brute force the password for a blockchain wallet from 2013.


We have used blockchain2john.py to create a $blockchain$ hash.

We also do not know how much is in the wallet, it could be 0.

We are using the command: ./hashcat blockchain.hash -a3 -w4 -i


Our hashcat rig has got to 10 characters and now we realise this is indeed a very long time to complete :-)

We know the password is a mixture of lowercase/uppercase/numbers/symbols.

We think its a capital letter word followed by 2 numbers and a symbol but unsure on the symbol.

For example, there are no $ or [ in the password.

We have narrowed the symbol used down to some possibilities: !, ;, : and @

So now we are going to try a combination/mask attack.


Our questions at this time:

How can we produce a mask attack that excludes all symbols except a few?

How can we produce something that will suit our needs?

How do we know if our commands passed into hashcat are working?

What is an example command for hashcat for a blockchain wallet?

Can we find the address without cracking the password?


Thanks
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#2
Use mask attack https://hashcat.net/wiki/doku.php?id=mask_attack
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#3
(12-07-2022, 12:47 AM)marc1n Wrote: Use mask attack https://hashcat.net/wiki/doku.php?id=mask_attack

Thanks. We have read the wiki for mask attack but we are unable to figure out how to specify reduced amount of symbols to use.
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#4
You will be required to create customer character sets. That would require to define parameters -1 to -4 for different case usage. So for example if you know the first letter is a capital and most likely not a vowel you can create that by defining -1.

Code:
hashcat -a 3 -m xxx -1 BCDFGHJKLMNPQRSTVWXYZ hashfile ?1

By defining -1 you can use it as you would any other specific character maskset using "?" and the number appended to that custom set. So to define 2 sets and use them in conjunction would be as the following:

Code:
hashcat -a 3 -m xxx -1 BCDFGHJKLMNPQRSTVWXYZ -2 !@#$%^&* hashfile ?1?l?l?l?l?l?l?d?d?2

The last snippet you would receive a password beginning with a uppercase then 6 lower case followed by 2 digits and finally a limited special character. Hope this helps.
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