T1127.001
Trusted Developer Utilities Proxy Execution: MSBuild
Description from ATT&CK
Adversaries may use MSBuild to proxy execution of code through a trusted Windows utility. MSBuild.exe (Microsoft Build Engine) is a software build platform used by Visual Studio. It handles XML formatted project files that define requirements for loading and building various platforms and configurations.(Citation: MSDN MSBuild)
Adversaries can abuse MSBuild to proxy execution of malicious code. The inline task capability of MSBuild that was introduced in .NET version 4 allows for C# or Visual Basic code to be inserted into an XML project file.(Citation: MSDN MSBuild)(Citation: Microsoft MSBuild Inline Tasks 2017) MSBuild will compile and execute the inline task. MSBuild.exe is a signed Microsoft binary, so when it is used this way it can execute arbitrary code and bypass application control defenses that are configured to allow MSBuild.exe execution.(Citation: LOLBAS Msbuild) https://www.aleksandrhovhannisyan.com/blog/how-to-add-a-copy-to-clipboard-button-to-your-jekyll-blog/
Atomic Tests
Atomic Test #1 - MSBuild Bypass Using Inline Tasks
Executes the code in a project file using. C# Example
Supported Platforms: windows
auto_generated_guid: 58742c0f-cb01-44cd-a60b-fb26e8871c93
Inputs:
| Name | Description | Type | Default Value |
|---|---|---|---|
| filename | Location of the project file | Path | PathToAtomicsFolder\T1127.001\src\T1127.001.csproj |
Attack Commands: Run with command_prompt!
1
2
C:\Windows\Microsoft.NET\Framework\v4.0.30319\msbuild.exe #{filename}
Dependencies: Run with powershell!
Description: Project file must exist on disk at specified location (#{filename})
Check Prereq Commands:
1
2
if (Test-Path #{filename}) {exit 0} else {exit 1}
Get Prereq Commands:
1
2
3
New-Item -Type Directory (split-path #{filename}) -ErrorAction ignore | Out-Null
Invoke-WebRequest "https://github.com/redcanaryco/atomic-red-team/raw/master/atomics/T1127.001/src/T1127.001.csproj" -OutFile "#{filename}"