Combinator Attack issue with rules

[undeath]

There is not "a rule" to simulate a hybrid attack Since OP is already confused about rules vs masks that info was not very helpful. But you are right, hybrid attacks don't actually support stdin, so only a0 with rules is possible.

cat append-digit.rule

Code:

$0
$1
$2
$3
$4
$5
$6
$7
$8
$9

Code:

combinator3 wordlist 4digitwordlist wordlist | hashcat -r append-digit.rule -r append-digit.rule -r append-digit.rule -r append-digit.rule [other options]