MSBuild is the build platform for Microsoft and Visual Studio, it is also can be utilized to build applications in some environments where Visual Studio is not installed, so it trusted by some antivirus software.
MSBuild can compile xml files in specific formats, so, to run our shellcode via MSBuild , we need a xml file like this.
PowerShell is a task automation and configuration management framework from Microsoft, consisting of a command-line shell and associated scripting language. Initially a Windows component only, known as Windows PowerShell, it was made open-source and cross-platform on 18 August 2016 with the introduction of PowerShell Core. The former is built on the .NET Framework, the latter on .NET Core.
Third-party developers can add cmdlets and providers to PowerShell. Cmdlets may be used by scripts and scripts may be packaged into modules.