hashcat -n 2 -m 0 -a 3 --pw-min 9 hashfile.txt ?l?l?l?l?l?l?l?l?l?l

-n = 2 threads -m 0 = md5 –pw-min 9 = minimal 9 characters hashfile.txt = is txt file where the hash is located ?l?l?l?l?l?l?l?l?l?l = lowercase password

Have fun!