Not without first knowing the salt they can't.
It's very possible that the salt may have also been compromised by the same method used to retrieve the hashes but salts most certainly are meant to be kept secret; at least to the same extent as the hashes themselves.
In cases where a single salt is used to generate multiple hashes
In addition to the salt being possibly unknown the method used to generate the hashes may also be unknown.
Just because it has recently become trivial to brute force short passwords from hashes generated by a couple types of commonly used hashing methods doesn't also make trivial the knowledge of how the hashes were generated and the value of the salt.