Csc.exe
Binary file used by .NET Framework to compile C# code
Paths
C:\Windows\Microsoft.NET\Framework\v4.0.30319\Csc.exeC:\Windows\Microsoft.NET\Framework64\v4.0.30319\Csc.exeC:\Windows\Microsoft.NET\Framework\v3.5\csc.exeC:\Windows\Microsoft.NET\Framework64\v3.5\csc.exeC:\Windows\Microsoft.NET\Framework\v2.0.50727\csc.exeC:\Windows\Microsoft.NET\Framework64\v2.0.50727\csc.exe
Commands
Compile
Use csc.exe to compile C# code, targeting the .NET Framework, stored in the specified .cs file and output the compiled version to the specified .exe path.
Use case: Compile attacker code on system. Bypass defensive counter measures.
Privileges: User
csc.exe -out:{PATH:.exe} {PATH:.cs}Compile
Use csc.exe to compile C# code, targeting the .NET Framework, stored in the specified .cs file and output the compiled version to a DLL file with the same name.
Use case: Compile attacker code on system. Bypass defensive counter measures.
Privileges: User
csc -target:library {PATH:.cs}Detection
- Sigma: https://github.com/SigmaHQ/sigma/blob/62d4fd26b05f4d81973e7c8e80d7c1a0c6a29d0e/rules/windows/process_creation/proc_creation_win_csc_susp_parent.yml
- Sigma: https://github.com/SigmaHQ/sigma/blob/62d4fd26b05f4d81973e7c8e80d7c1a0c6a29d0e/rules/windows/process_creation/proc_creation_win_csc_susp_folder.yml
- Elastic: https://github.com/elastic/detection-rules/blob/61afb1c1c0c3f50637b1bb194f3e6fb09f476e50/rules/windows/defense_evasion_dotnet_compiler_parent_process.toml
- Elastic: https://github.com/elastic/detection-rules/blob/82ec6ac1eeb62a1383792719a1943b551264ed16/rules/windows/defense_evasion_execution_msbuild_started_unusal_process.toml
- IOC: Csc.exe should normally not run as System account unless it is used for development.