Keytab Extraction

Once you have captured packets you can use Wireshark to analyze them in many case decryption of traffic is needed in order to analyze correctly an exchange.

How to Extract a keytab containing your domain's passwords

There are two ways to obtain a keytab from an Active Directory Domain with Samba:

Using Samba4

To use samba4, it needs to be a domain controller for your domain. If it's not the case check how to join Samba4 as domain controller

net vampire NETBIOS_DOMAIN_NAME --realm=REALM -Uadministrator

Or, for a recent GIT checkout (later than 2010/10/23):

samba-tool vampire NETBIOS_DOMAIN_NAME --realm=REALM -Uadministrator

If everything is set up correctly, it should just work. If not, check /etc/krb5.conf in particular - ensure it can reach the KDC by setting:

[libdefaults]
dns_lookup_kdc = true

Then, to extract the keytab run

net export keytab PATH_TO_KEYAB

or:

samba-tool export keytab PATH_TO_KEYAB

It will write out a keytab in the path specified, containing the current keys for every host.

Samba3

To dump a keytab, join the domain and then run:

net rpc vampire keytab /path/to/keytab/file

Note that the path to the keytab file needs to be an absolute path.