If you know that the password has a length of 8 and contains only lower case alphanumeric then the best mask would be: -1 ?l?d ?1?1?1?1?1?1?1?1.
A dictionary attack could be faster, but that depends on the size of the dictionary.
Not sure why you used 3x ?l at the end of your mask, I mean yeah you know the password but than you just could have used: ?l?d?l?d?l?l?l?l.
Edit: Since I'm a beginner myself please correct any mistakes.
A dictionary attack could be faster, but that depends on the size of the dictionary.
Not sure why you used 3x ?l at the end of your mask, I mean yeah you know the password but than you just could have used: ?l?d?l?d?l?l?l?l.
Edit: Since I'm a beginner myself please correct any mistakes.