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


Keywords
agent, c2, command-and-control, golang, http2, post-exploitation
License
GPL-3.0
Install
go get github.com/Ne0nd0g/merlin

Documentation

CodeQL GoReportCard License: GPL v3 Release Downloads Twitter Follow

Merlin

Merlin Logo

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:

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.

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

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