Merlin

Merlin is a cross-platform post-exploitation Command & Control server and agent written in Go.

Highlighted features:

• merlin-cli command line interface over gRPC to connect to the Merlin Server facilitating multi-user support
• Supported Agent C2 Protocols: http/1.1 clear-text, http/1.1 over TLS, HTTP/2, HTTP/2 clear-text (h2c), http/3 (http/2 over QUIC)
• Peer-to-peer (P2P) communication between Agents with bind or reverse for SMB, TCP, and UDP
• Configurable agent data encoding and encryption transforms: AES, Base64, gob, hex, JWE, RC4, and XOR
  • JWE transform use PBES2_HS512_A256KW PBES2 (RFC 2898) with HMAC SHA-512 as the PRF and AES Key Wrap (RFC 3394) using 256-bit keys for the encryption scheme
• Configurable agent authenticators:
  • None: No authentication
  • OPAQUE: Asymmetric Password Authenticated Key Exchange (PAKE)
• Encrypted JWT for message authentication
• Configurable Agent message data padding to combat beaconing detections based on a fixed message size
• Execute .NET assemblies in-process with invoke-assembly or in a sacrificial process with execute-assembly
• Execute arbitrary Windows executables (PE) in a sacrificial process with execute-pe
• Various shellcode execution techniques: CreateThread, CreateRemoteThread, RtlCreateUserThread, QueueUserAPC
• Integrated Donut, sRDI, and SharpGen support
• Dynamically change the Agent's JA3 hash
• Mythic support
• Documentation & Wiki

An introductory blog post can be found here: https://medium.com/@Ne0nd0g/introducing-merlin-645da3c635a

Supporting Repositories:

• Merlin Agent - Agent source code
• Merlin Agent DLL - Agent DLL source code
• Merlin CLI - Command line interface for Merlin
• Merlin Documentation - Documentation source code
• Merlin on Mythic - Merlin agent for Mythic Framework
• Merlin Docker - Base Docker image for for Merlin images
• Merlin Message - A Go library for Merlin messages exchanged between a Merlin Server and Agent

Quick Start

1. Download the latest version of Merlin Server from the releases section

   The Server package contains compiled versions of the CLI and Agent for all the major operating systems in the data/bin directory

2. Extract the files with 7zip using the x function The password is: merlin

3. Start Merlin

4. Start the CLI

5. Configure a listener

6. Deploy an agent. See Agent Execution Quick Start Guide for examples

7. Pwn, Pivot, Profit

   mkdir /opt/merlin;cd /opt/merlin
   wget https://github.com/Ne0nd0g/merlin/releases/latest/download/merlinServer-Linux-x64.7z
   7z x merlinServer-Linux-x64.7z
   sudo ./merlinServer-Linux-x64
   ./data/bin/merlinCLI-Linux-x64
   

Mythic

Merlin can be integrated and used as an agent with the Mythic a collaborative, multi-platform, red teaming framework.

Visit the Merlin on Mythic repository in the MythicAgents organization to get started.

Misc.

• To compile Merlin from source, view the Custom Build page
• For a full list of available commands:
  • Main Menu
  • Listener Menu
  • Agent Menu
  • Module Menu
• View the Frequently Asked Questions page
• View the Blog Posts page for additional information

Slack

Join the #merlin channel in the BloodHoundGang Slack to ask questions, troubleshoot, or provide feedback.

JetBrains

Thanks to JetBrains for kindly sponsoring Merlin by providing a Goland IDE Open Source license