88 - Kerberos

First enumeration using nmap

nmap -p 88 --script=krb5-enum-users --script-args krb5-enum-users.realm="access.offsec",userdb=/usr/share/wordlists/seclists/Usernames/cirt-default-user
    PORT   STATE SERVICE
    88/tcp open  kerberos-sec
    | krb5-enum-users: 
    | Discovered Kerberos principals
    |     [e-mail]
    |     [e-mail]
    |_    [e-mail]