REMnux MCP Server

remnux-mcp-server

MCP server for using the REMnux malware analysis toolkit via AI assistants.

Overview

This server enables AI assistants (Claude Code, OpenCode, Cursor, etc.) to execute malware analysis tools on a REMnux system. It supports three deployment scenarios:

1. AI tool on your machine, REMnux as Docker/VM — MCP server runs on your machine, reaches into REMnux over Docker exec or SSH
2. AI tool and MCP server both on REMnux — everything runs locally on the same REMnux system (simplest setup)
3. AI tool on your machine, MCP server on REMnux — MCP server runs inside REMnux, your AI tool connects over HTTP

Beyond raw command execution, the server encodes malware analysis domain expertise:

• Recommends the right tools for each file type (suggest_tools) and retrieves usage flags for any installed tool (get_tool_help)
• Runs appropriate tool chains automatically (analyze_file) with structured output and IOC extraction
• Uses neutral language to counteract confirmation bias in AI-generated verdicts

For additional tool documentation, you can optionally enable the REMnux docs MCP server.

Architecture

Three deployment scenarios are supported depending on where the MCP server and AI assistant run.

Scenario 1: Server on Analyst's Machine

The MCP server runs on the analyst's workstation and connects to a separate REMnux system over Docker exec or SSH.

+--------------------------------------------------------------------+
|  Analyst's Machine                                                 |
|                                                                    |
|  +----------------+     +--------------------------------------+   |
|  |  AI Assistant  |---->|  remnux-mcp-server (npm package)     |   |
|  | (Claude Code,  | MCP |                                      |   |
|  |  Cursor, etc)  |     |  - Blocked command patterns          |   |
|  +----------------+     |  - Dangerous pipe blocking           |   |
|                         |  - Path sandboxing (opt-in)          |   |
|                         +------|-------------------------------+   |
|                                |                                   |
|                    +-----------+----------+                        |
|                    v                      v                        |
|            +--------------+      +--------------+                  |
|            | Docker Exec  |      |     SSH      |                  |
|            | (container)  |      |    (VM)      |                  |
|            +------+-------+      +------+-------+                  |
|                   |                     |                           |
+-------------------|---------------------|---------------------------+
                    v                     v
             +-----------+        +-----------+
             |  REMnux   |        |  REMnux   |
             | Container |        |    VM     |
             +-----------+        +-----------+

Scenario 2: Everything on REMnux

The AI assistant and MCP server both run on the REMnux system. The server uses the Local connector with stdio transport — no network, no Docker exec, no SSH. This is the simplest setup.

+-------------------------------+
|  REMnux (VM or bare metal)    |
|                               |
|  +----------------+           |
|  |  AI Assistant  |           |
|  | (Claude Code,  |   stdio   |
|  |  OpenCode)     +--------+  |
|  +----------------+        |  |
|                            v  |
|  +-------------------------+  |
|  | remnux-mcp-server       |  |
|  |  --mode=local (default) |  |
|  |                         |  |
|  |  - Local connector      |  |
|  |  - Security layers      |  |
|  +-------------------------+  |
|                               |
|  REMnux tools (native)        |
+-------------------------------+

Scenario 3: Server Inside REMnux

The MCP server runs inside the REMnux VM or container using the Local connector. The AI assistant connects over the network via Streamable HTTP transport. This is the deployment scenario used by REMnux salt-states.

+----------------+   Streamable HTTP   +------------------------------+
|  AI Assistant  |----(network)------->|  REMnux (VM/Container)       |
| (Claude Code,  |                     |                              |
|  Cursor, etc)  |                     |  +------------------------+  |
+----------------+                     |  | remnux-mcp-server      |  |
                                       |  |  --mode=local          |  |
                                       |  |  --transport=http      |  |
                                       |  |                        |  |
                                       |  |  - Local connector     |  |
                                       |  |  - Security layers     |  |
                                       |  +------------------------+  |
                                       |                              |
                                       |  REMnux tools (native)       |
                                       +------------------------------+

Quick Start

Prerequisites: Node.js >= 18, plus Docker (for container mode) or SSH access (for VM mode).

Optional: For additional tool documentation beyond what suggest_tools and get_tool_help provide, you can enable the REMnux docs MCP server alongside this one.

Choose the scenario that matches your setup.

Scenario 1: AI Tool on Your Machine, REMnux as Docker/VM

Your AI assistant (Claude Code, Cursor, etc.) runs on your physical machine. The MCP server also runs on your machine and reaches into REMnux over Docker exec or SSH to run analysis tools.

With Docker (recommended):

# Start REMnux container
docker run -d --name remnux remnux/remnux-distro:noble

# Add to Claude Code (stdio transport — server runs as a child process)
claude mcp add remnux -- npx @remnux/mcp-server --mode=docker --container=remnux

With a VM (SSH):

# Key-based auth via SSH agent (default) — ensure your key is loaded:
# ssh-add ~/.ssh/your_key
claude mcp add remnux -- npx @remnux/mcp-server --mode=ssh --host=YOUR_VM_IP --user=remnux

# Password auth
claude mcp add remnux -- npx @remnux/mcp-server --mode=ssh --host=YOUR_VM_IP --user=remnux --password=YOUR_PASSWORD

Claude Desktop / Cursor config (add to MCP settings JSON):

{
  "mcpServers": {
    "remnux": {
      "command": "npx",
      "args": ["@remnux/mcp-server", "--mode=docker", "--container=remnux"]
    }
  }
}

The upload_from_host and download_file tools handle file transfer between your machine and REMnux. You can optionally mount shared Docker volumes, but the built-in tools are simpler and maintain container isolation.

Scenario 2: AI Tool and MCP Server Both on REMnux

Your AI assistant (OpenCode, Claude Code, etc.) runs directly on the REMnux VM or container. The MCP server runs on the same system using the local connector — no network, no Docker exec, no SSH. Tools execute natively.

Stdio transport (same machine, recommended):

Add the server to your AI tool's MCP config. The tool launches it automatically via stdio:

{
  "mcpServers": {
    "remnux": {
      "command": "remnux-mcp-server"
    }
  }
}

Local mode is the default — no --mode flag needed. The default paths (/home/remnux/files/samples and /home/remnux/files/output) match the REMnux filesystem layout, so no additional configuration is needed.

In local mode, analysis tools also accept absolute file paths, so you can reference files anywhere on the filesystem without uploading them first.

Scenario 3: AI Tool on Your Machine, MCP Server on REMnux (HTTP)

Your AI assistant runs on your physical machine, but instead of the MCP server also running on your machine (Scenario 1), it runs inside REMnux and listens on a network port. Your AI tool connects over HTTP.

Use this when you want REMnux to be self-contained — the MCP server and analysis tools are co-located, and your AI tool just needs network access.

On REMnux (start the server):

export MCP_TOKEN=$(openssl rand -hex 32)
remnux-mcp-server --mode=local --transport=http --http-host=0.0.0.0
echo "Token: $MCP_TOKEN"  # save this for the client

On your machine (connect Claude Code):

claude mcp add remnux --transport http http://REMNUX_IP:3000/mcp \
  --header "Authorization: Bearer YOUR_TOKEN"

Claude Desktop / Cursor config:

{
  "mcpServers": {
    "remnux": {
      "type": "streamable-http",
      "url": "http://REMNUX_IP:3000/mcp",
      "headers": {
        "Authorization": "Bearer YOUR_TOKEN"
      }
    }
  }
}

Security Notes (HTTP transport)

• Always use a token in production. Without --http-token or MCP_TOKEN, any network client can execute commands.
• Default bind is 127.0.0.1 — set --http-host=0.0.0.0 to allow network access.
• Generate strong tokens: openssl rand -hex 32
• Use MCP_TOKEN env var to avoid exposing the token in process listings.
• For HTTPS, place a reverse proxy (nginx, caddy) in front of the MCP server. The bearer token travels in plaintext over HTTP without this.
• DNS rebinding protection is automatically enabled when binding to localhost.

CLI Options

Flag	Description	Default
--mode	Connection mode: local, docker, or ssh	local
--container	Docker container name/ID (for docker mode)	remnux
--host	SSH host (for ssh mode)	-
--user	SSH user (for ssh mode)	remnux
--port	SSH port (for ssh mode)	22
--password	SSH password (for ssh mode; uses SSH agent if omitted)	-
--samples-dir	Samples directory path inside REMnux	/home/remnux/files/samples
`--output-d

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README truncated. View full README on GitHub.