LOTP

MSBuild

cli config-file input-file eval-sh

References

• https://learn.microsoft.com/en-us/visualstudio/msbuild/msbuild
• https://learn.microsoft.com/en-us/visualstudio/msbuild/customize-by-directory

MSBuild is a platform for building C#/.NET applications. It comes together with Visual Studio, but can be installed separately.

The configuration is a XML file with .csproj or .proj extension.

It can be executed by running either msbuild <file> or dotnet build <file>.

Sample build.proj config:

<Project DefaultTargets="Build">
  <Target Name="Build">
    <Exec Command="whoami" /> <!-- Code goes here -->
  </Target>
</Project>

You can also inject into MSBuild process without modifying any existing file and creating a new one insted. For this to be possible, the original project has to either import Microsoft.Common.props or it needs to be an SDK style project.

MSBuild searches upwards for a Directory.Build.props file from the project directory, and imports it automatically.

When imported, you can inject into the process using BeforeTargets keyword.

Sample Directory.Build.props

<Project>
  <Target Name="malicious" BeforeTargets="Build">
    <Exec Command="echo 'injected!'" />  <!-- Code goes here -->
  </Target>
</Project>