07-13-2018, 05:19 PM
If i understand correctly, you are trying to recover a brainwallet via the original passphrase/seed? Tools already exist for this, and I am able to do this already, though not with hashcat. The one that comes to mind as being capable immediately would be RyanC's brainflayer, designed specifically for cracking brain wallets.
https://github.com/ryancdotorg/brainflayer
https://github.com/ryancdotorg/brainflayer