Unknown hash and original: not identifieably, is hashcat able to find out?

[rico]

Is it possible to had hashcat the hash and a text file with the unhashed value, and hashcat is able to identify it?

Sort of. Put the passphrase (unhashed value) into a text file called words.txt in the hashcat folder

hashcat -m XXXX -a 0 yourhashvalue words.txt

Go through all the supported types (XXXX above) until you get a hit. Obviously try and match the hash with the right length to be in with a shot first too.

E.g.:
SHA-1 hash of blahblahblah is 25f683212e147aad3a11a8dd89b8de988be57349

Code:

hashcat64.exe -m 100 -a 0 25f683212e147aad3a11a8dd89b8de988be57349 words.txt
hashcat (v3.30) starting...
<SNIP>
The wordlist or mask you are using is too small.
Therefore, hashcat is unable to utilize the full parallelization power of your device(s).
The cracking speed will drop.
Workaround: https://hashcat.net/wiki/doku.php?id=frequently_asked_questions#how_to_create_more_work_for_full_speed

INFO: approaching final keyspace, workload adjusted

25f683212e147aad3a11a8dd89b8de988be57349:blahblahblah

Session..........: hashcat
Status...........: Cracked
Hash.Type........: SHA1
Hash.Target......: 25f683212e147aad3a11a8dd89b8de988be57349