UAC-BOF-Bonanza : Elevating Access With Advanced Bypass Methods

This repository serves as a collection of public UAC bypass techniques that have been weaponized as BOFs. A single module which integrates all techniques has been provided to use the BOFs via the Havoc C2 Framework.

A extension.json file has also been provided for each bypass technique for use in Sliver. See the section of the readme titled Greetz/Credit for all references/code that was used in this project.

UAC Bypass	Description
`CmstpElevatedCOM`	Creates an elevated ICMLuaUtil COM object and calls its `ShellExec` function to execute the provided file on disk.
`ColorDataProxy`	Creates an elevated ICMLuaUtil COM object and calls its `SetRegistryStringValue` function to write the location of the provided file to the `DisplayCalibrator` registry value residing in HKLM. It will then create an elevated IColorDataProxy COM object and call its `LaunchDccw` function, resulting in the execution of the provided file.
`EditionUpgradeManager`	Modifies the “Environment\windir” registry key, creates a elevated IEditionUpgradeManager COM object, and then calls the `AcquireModernLicenseWithPreviousId` function from the elevated COM object to execute the provided file.
`SilentCleanupWinDir`	Modifies the “Environment\windir” registry key and executes the SilentCleanup scheduled task via schtasksrun by @TrustedSec.
`RegistryShellCommand`	Modifies the “ms-settings\Shell\Open\command” registry key and executes an auto-elevated EXE (ComputerDefaults.exe).
`TrustedPathDLLHijack`	Creates fake windows directory `C:\Windows \`, copies supplied DLL to location, and executes auto-elevated EXE (ComputerDefaults.exe).
`SspiUacBypass`	Forges a token from a fake network authentication though SSPI Datagram Contexts. It will then impersonate the forged token and use CreateSvcRpc by @x86matthew to create a new SYSTEM service. Original research and code is from @splinter_code.

The BOFs can be utilized by running their corresponding subcommands in the Havoc C2 module.

To use, simply run make and then load the module into Havoc using the script manager. See below for usage information and examples:

15/02/2024 18:07:05 [chippy] Demon » help uac-bypass

 - Command       :  uac-bypass
 - Description   :  Havoc UAC Bypass Module
 - Usage         :  uac-bypass [subcommand] (args)
 - Required Args :  2

  Command                   Description      
  ---------                 -------------     
  trustedpath               Perform UAC bypass via fake windows directory with ComputerDefaults.exe and Secur32.dll
  silentcleanup             Perform UAC bypass via the "Environment\windir" registry key and SilentCleanup scheduled task
  sspidatagram              Perform UAC bypass via SSPI Datagram Contexts
  registrycommand           Perform UAC bypass via modifying the "ms-settings\Shell\Open\command" registry key
  elevatedcom               Perform UAC bypass via the ICMLuaUtil elevated COM interface
  colordataproxy            Perform UAC bypass via ColorDataProxy and elevated ICMLuaUtil COM interface
  editionupgrade            Perform UAC bypass via the "Environment\windir" registry key and elevated IEditionUpgradeManager COM interface

Additionally, extension.json files have been provided for each UAC bypass method if you wish to use them with Sliver C2. See below for sample instructions on how to load and use the extensions:

# Copy folder for desired UAC bypass to the sliver extensions folder
cp -rp ~/dev/UACBypasses/SspiUacBypass /root/.sliver-client/extensions/
# CD into the new extension folder and run make
cd /root/.sliver-client/extensions/SspiUacBypass/; make
# From sliver client cli, load extension by providing new path
extensions load /root/.sliver-client/extensions/SspiUacBypass

Finally, standalone implementations of each UAC bypass have also been provided. These will automatically be built by mingw when running the make command.

OpSec/Usage Considerations

All UAC bypasses were tested and confirmed working on Windows 11 (23H2) and Windows 10 (22H2).
As these are all public UAC bypass techniques, their behavior should be detected by most competent SOCs and EDR solutions. See this blog post from Elastic demonstrating detections for multiple bypasses in this project.
This is a random project you found on GitHub. Read the source code and confirm it’s up to your standards before using. If you notice anything in the code that could cause stability issues, feel free to post a pull request that fixes it.

Varshini

Varshini is a Cyber Security expert in Threat Analysis, Vulnerability Assessment, and Research. Passionate about staying ahead of emerging Threats and Technologies.