hashcat recovers null results

[Kangaroot]

I was hoping someone can explain hashcat behaviour.

I have bunch of hashes (sha512($pass.$salt)) which I run against dictionary and hashcat recovers them as null. They can be different hashes with different salts, but hashcat still recovers them as null.

Basically, output looks like [hash]:[salt]:      ...and then nothing.

Am I missing out something?

[DanielG]

Just to be really really sure, if you do sha512($salt) on for example https://passwordsgenerator.net/sha512-hash-generator/ you don't get the hash in your output?

[Kangaroot]

Yes, it does actually. What would that mean?

[DanielG]

That hashcat is correctly showing the results. There is no password for those hashes you have, only a salt. Depending on your source this might be logical.

[Kangaroot]

Makes sense, thank you, Daniel.

[Kangaroot]

Although I don't fully understand, why there will need to be salt if no password?

I believe this is something to do with 'Windows Authentication' when users authenticate using Windows logon. But again why unique salt needed to be generated and as a password used encoded salt?!