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

Highlighted features:

• Supported 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)
• Server and Agent: Windows, Linux, macOS (Darwin), MIPS, ARM or anything Go can natively build
  • Windows DLL Agent
• Domain Fronting
• 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
• OPAQUE Asymmetric Password Authenticated Key Exchange (PAKE)
• Encrypted JWT for authentication
• Agent traffic is an encrypted JWE using PBES2 (RFC 2898) with HMAC SHA-512 as the PRF and AES Key Wrap (RFC 3394) using 256-bit keys for the encryption scheme. (PBES2_HS512_A256KW)
• Integrated Donut, sRDI, and SharpGen support
• C2 traffic message padding to combat beaconing detections based on a fixed message size
• 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

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

   The Server package contains a compiled 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. Configure a listener

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

6. 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
   

The Merlin Agent is kept in its own repository so that it can easily be retrieved and compiled:

go get github.com/Ne0nd0g/merlin-agent

The Windows DLL Agent is also kept in a separate repository. See the DLL Agent documentation for building instructions.

The Merlin server is a self-contained command line program that requires no installation. You just simply download it and run it. The command-line interface only works great if it will be used by a single operator at a time. The Merlin agent can be controlled through Mythic, which features a web-based user interface that enables multiplayer support, and a slew of other features inherent to the project.

Visit the Merlin repository in the MythicAgents organizaiton to get started.

• The latest development build of Merlin can be downloaded from AppVeyor
• 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

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

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