Where did you get the information from that it needs to have a "Veracrypt" string in it?
This is not true as far as I can tell.
You are basically searching for something (the "Veracrypt" thing) that shouldn't be there if you extracted it correctly.
There are also some TrueCrypt example data on the example wiki (yeah, I know TrueCrypt is not VeraCrypt, but they are very similar when it comes to extracting etc) and also they do not have any hardcoded string in it (or as you would say it's just some random letters and symbols, and that is exactly what is to be expected).
https://hashcat.net/wiki/doku.php?id=example_hashes
This is not true as far as I can tell.
You are basically searching for something (the "Veracrypt" thing) that shouldn't be there if you extracted it correctly.
There are also some TrueCrypt example data on the example wiki (yeah, I know TrueCrypt is not VeraCrypt, but they are very similar when it comes to extracting etc) and also they do not have any hardcoded string in it (or as you would say it's just some random letters and symbols, and that is exactly what is to be expected).
https://hashcat.net/wiki/doku.php?id=example_hashes