/merlin

Merlin is a cross-platform post-exploitation HTTP/2 Command & Control server and agent written in golang.

Primary LanguageGoGNU General Public License v3.0GPL-3.0

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Merlin

Merlin Logo

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
  • 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

Quick Start

  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
    

Agents

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.

Mythic

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.

Misc.

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

JetBrains Logo GoLand Logo