Basically, the hybrid attack is just a Combinator attack. One side is simply a dictionary, the other is the result of a Brute-Force attack. In other words, the full Brute-Force keyspace is either appended or prepended to each of the words from the dictionary. That's why it's called “hybrid”.
Alternatively you can use Mask attack or Rule-based attack to replace the Brute-Force side.
If your example.dict contains:
password hello
The configuration:
$ ... -a 6 example.dict ?d?d?d?d
generates the following password candidates:
password0000 password0001 password0002 . . . password9999 hello0000 hello0001 hello0002 . . . hello9999
It also works on the opposite side!
The configuration:
$ ... -a 7 ?d?d?d?d example.dict
generates the following password candidates:
0000password 0001password 0002password . . . 9999password 0000hello 0001hello 0002hello . . . 9999hello
We can utilize the rule engine in hashcat to emulate the Hybrid attack.
This section has moved into a dedicated wiki page: Using rules to emulate hybrid attack.