I want to brute force incrementally with two digits appended

[betsyjackson]

Suppose I want to brute force a keyspace from aaaa - zzzzzzzzzz. The first guesses are four characters, but the last guesses are ten characters. I also want to append two numbers to every guess.

aaaa00
aaaa01
aaaa02
...
zzzzzzzzzz97
zzzzzzzzzz98
zzzzzzzzzz99

Does anyone know how I would achieve that?

[philsmd]

You can use a .hcmask file for this (https://hashcat.net/wiki/mask_attack#hashcat_mask_files):

Code:

hashcat -m 0 -a 3 hash_file.txt mask_file.hcmask

content of the file "mask_file.hcmask":

Code:

?l?l?l?l?d?d
?l?l?l?l?l?d?d
?l?l?l?l?l?l?d?d
?l?l?l?l?l?l?l?d?d
?l?l?l?l?l?l?l?l?d?d
?l?l?l?l?l?l?l?l?l?d?d
?l?l?l?l?l?l?l?l?l?l?d?d

this assumes that only lower-case letters should be used, you can change that easily if you need to