it already fixes the problem, in any case what they did it was to modify the shadow, password, gshadow and group files, for that reason I think that it can have been through ispconfig server, because no other user has the possibility of modifying these files.
The other errors that appeared they were by the same problem, i solved the problem entering in single mode, and replacing the archives modified with those of backups old files, but now it appears in the name of session, to initiate the session in ssh for example, a messages as :
I have no name!@machinename:~$
I did not solve this problem yet ...
well my friend i will continue analyzing this and other problems and i'm writing them ... thank you for all the answers ...