Adversaries may attempt to make payloads difficult to discover and analyze by delivering files to victims as uncompiled code. Text-based source code files may subvert analysis and scrutiny from protections targeting executables/binaries. These payloads will need to be compiled before execution; typically via native utilities such as csc.exe or GCC/MinGW.(Citation: ClearSky MuddyWater Nov 2018) Source code payloads may also be encrypted, encoded, and/or embedded within other files, such as those delivered as a [Phishing](https://attack.mitre.org/techniques/T1566). Payloads may also be delivered in formats unrecognizable and inherently benign to the native OS (ex: EXEs on macOS/Linux) before later being (re)compiled into a proper executable binary with a bundled compiler and execution framework.(Citation: TrendMicro WindowsAppMac)
Compile C# code using csc.exe binary used by .NET Upon execution an exe named T1027.004.exe will be placed in the temp folder
Supported Platforms: Windows
auto_generated_guid: ffcdbd6a-b0e8-487d-927a-09127fe9a206
| Name | Description | Type | Default Value | |——|————-|——|—————| | output_file | Output compiled binary | path | C:\Windows\Temp\T1027.004.exe| | input_file | C# code that launches calc.exe from a hidden cmd.exe Window | path | PathToAtomicsFolder\T1027.004\src\calc.cs|
1
command_prompt
!C:\Windows\Microsoft.NET\Framework64\v4.0.30319\csc.exe /out:#{output_file} "#{input_file}"
del #{output_file} >nul 2>&1
1
powershell
!1
if (Test-Path "#{input_file}") {exit 0} else {exit 1}
1
2
New-Item -Type Directory (split-path "#{input_file}") -ErrorAction ignore | Out-Null
Invoke-WebRequest "https://github.com/redcanaryco/atomic-red-team/raw/master/atomics/T1027.004/src/calc.cs" -OutFile "#{input_file}"
When C# is compiled dynamically, a .cmdline file will be created as a part of the process. Certain processes are not typically observed compiling C# code, but can do so without touching disk. This can be used to unpack a payload for execution. The exe file that will be executed is named as T1027.004_DynamicCompile.exe is contained in the ‘bin’ folder of this atomic, and the source code to the file is in the ‘src’ folder. Upon execution, the exe will print ‘T1027.004 Dynamic Compile’.
Supported Platforms: Windows
auto_generated_guid: 453614d8-3ba6-4147-acc0-7ec4b3e1faef
| Name | Description | Type | Default Value | |——|————-|——|—————| | input_file | exe program containing dynamically compiled C# code | path | PathToAtomicsFolder\T1027.004\bin\T1027.004_DynamicCompile.exe|
1
powershell
!1
Invoke-Expression "#{input_file}"
1
powershell
!1
if (Test-Path "#{input_file}") {exit 0} else {exit 1}
1
Invoke-WebRequest https://github.com/redcanaryco/atomic-red-team/raw/master/atomics/T1027.004/bin/T1027.004_DynamicCompile.exe -OutFile "#{input_file}"
Compile a c file with either gcc or clang on FreeBSD, Linux or Macos.
Supported Platforms: Linux, macOS
auto_generated_guid: d0377aa6-850a-42b2-95f0-de558d80be57
| Name | Description | Type | Default Value | |——|————-|——|—————| | input_file | source file | path | PathToAtomicsFolder/T1027.004/src/T1027-004-test.c|
1
sh
!1
2
gcc #{input_file} && ./a.out
clang #{input_file} && ./a.out
1
sh
!1
if [ -e #{input_file} ]; then exit 0; else exit 1; fi
1
wget https://github.com/redcanaryco/atomic-red-team/raw/master/atomics/T1027.004/src/T1027-004-test.c -O "#{input_file}"
Compile a c file with either gcc or clang on FreeBSD, Linux or Macos.
Supported Platforms: Linux, macOS
auto_generated_guid: da97bb11-d6d0-4fc1-b445-e443d1346efe
| Name | Description | Type | Default Value | |——|————-|——|—————| | input_file | source file | path | PathToAtomicsFolder/T1027.004/src/T1027-004-test.cc|
1
sh
!1
2
g++ #{input_file} && ./a.out
clang++ #{input_file} && ./a.out
1
sh
!1
if [ -e #{input_file} ]; then exit 0; else exit 1; fi
1
wget https://github.com/redcanaryco/atomic-red-team/raw/master/atomics/T1027.004/src/T1027-004-test.cc -O #{input_file}
Compile a go file with golang on FreeBSD, Linux or Macos.
Supported Platforms: Linux, macOS
auto_generated_guid: 78bd3fa7-773c-449e-a978-dc1f1500bc52
| Name | Description | Type | Default Value | |——|————-|——|—————| | input_file | source file | path | PathToAtomicsFolder/T1027.004/src/T1027-004-test.go|
1
sh
!1
go run #{input_file}
1
sh
!1
if [ -e #{input_file} ]; then exit 0; else exit 1; fi
1
wget https://github.com/redcanaryco/atomic-red-team/raw/master/atomics/T1027.004/src/T1027-004-test.go -O #{input_file}