What if you create a list of 6 character candidates, how large would that be?
Then you could create a rule file where you append each of the allowed characters like
$0
$1
$2
.
.
$9
$a
$b
.
.
$z
$A
$B
.
.
$Z
It would mean, though, that you would miss out on some candidates like abcdef0, 123456G etc.
Another option could be to create your wordlist with digits and lowercase only, and then use a mix of toggle rules.
Now that I think about it.... Maybe create 2 wordfiles. One with all possible 3 character candidates and one with all 4 character candidates and then run them together in a combinator attack -a1 in hashcat?
Then you could create a rule file where you append each of the allowed characters like
$0
$1
$2
.
.
$9
$a
$b
.
.
$z
$A
$B
.
.
$Z
It would mean, though, that you would miss out on some candidates like abcdef0, 123456G etc.
Another option could be to create your wordlist with digits and lowercase only, and then use a mix of toggle rules.
Now that I think about it.... Maybe create 2 wordfiles. One with all possible 3 character candidates and one with all 4 character candidates and then run them together in a combinator attack -a1 in hashcat?