How to Create the Rules for This Password Structure

[rustyshackleford]

This sounds like the Xfinity default password format. The way I accomplished it was to setup a ruleset that puts the numbers in the middle of an already combined wordlist using the inset rule. It's fairly simple to do, an example of a word and rule combo would look like this:

Word:
creekbasket

Rule:
i58 i69 i73 i87

Thank you for your reply! Yes, its a Cisco DPC3941B router and the service is xfinity. Is the dictionary you used online? I would love to use that one! Also, I am new to the hashcat rules: do those rules mean insert 8637 at spaces 5, 6, 7, and 8? But if I want to go through all the combos of numbers do you know how I would do that? For example I would want to go systematically like this:

apple0000anchor
apple0000basket
.....
apple0000zygote
apple0001anchor
.....
apple9999zygote
brick0000anchor

etc. So the last word changes 5000 times before the last number goes up 1, and so on.