Basic hashcat mask syntax

[philsmd]

Let me explain this:
if you use the mask ?1?1?1?1?1?1?1?1 together with --increment, what hashcat really does is run this set of masks one after the other:

Code:

?1
?1?1
?1?1?1
?1?1?1?1
?1?1?1?1?1
?1?1?1?1?1?1
?1?1?1?1?1?1?1
?1?1?1?1?1?1?1?1

it's comparable to when you start hashcat first with the mask ?1, then ?1?1, then ?1?1?1, then ?1?1?1?1... and finally ?1?1?1?1?1?1?1?1 (except that you do not need to restart it manually and the whole initialization/cleanup/termination phase will be done only once)

For the first set of masks the keyspace is very low... that is why a warning will be shown.
Something as small as just "?1" doesn't really give the GPU enough work to do. That is why the warning is shown for all masks with small keyspace/length.

You shouldn't worry too much about it... if you really need to run a small mask, you just need to remember that it won't reach the maximum speed.