Horizon

Project Overview: This project, codenamed “Horizon,” is a proof-of-concept Remote Administration Tool developed entirely in Rust. The primary motivation was to explore Rust’s power and safety in the context of offensive security tooling. Unlike traditional tools written in C or C++, Horizon leverages Rust’s memory safety guarantees to eliminate entire classes of vulnerabilities like buffer overflows, while its performance and concurrency features allow for a highly efficient and resilient Command & Control (C2) infrastructure. The tool is designed for educational use and as a resource for ethical hackers and red team operators.

Objectives

1. Leverage Rust for Security: To build a robust and secure agent (implant) that is inherently resistant to memory corruption bugs, making it more stable and harder to exploit.
2. Develop a Modern C2 Framework: Create an asynchronous Command & Control server capable of handling numerous simultaneous connections with low resource overhead.
3. Explore Stealth Techniques: Research and implement methods for evasive communication and on-disk presence, focusing on making the agent difficult to detect by conventional security solutions.

Features

1. Asynchronous C2 Server:

   • Built using the Tokio runtime, the C2 server is fully asynchronous and can manage thousands of concurrent agent connections without breaking a sweat.
   • Features a modular, command-based interface for interacting with active agents.

2. Encrypted & Resilient Communication:

   • All communications between the agent and the C2 server are protected with end-to-end encryption (e.g., AES-256 GCM) to prevent eavesdropping or hijacking.
   • The agent uses techniques like jitter and beaconing to blend in with normal network traffic.

3. Cross-Platform Agent:

   • The agent is written in platform-agnostic Rust where possible, with specific modules for OS interaction, allowing it to be compiled for Windows, Linux, and macOS targets.

4. In-Memory Execution:

   • The tool supports capabilities to reflectively load and execute modules directly in memory, minimizing the on-disk footprint and evading filesystem-based antivirus scans.

Technology Stack

• Core Language: Rust
• Asynchronous Runtime: Tokio
• Serialization: Serde for structured data communication between agent and C2.
• Encryption: aes-gcm and x25519-dalek crates for secure key exchange and communication.
• C2 Interface: A simple command-line interface built with Rust for operator control.
• Agent Payload: Pure Rust with minimal dependencies to ensure a small binary size.

Outcome

The project successfully produced a stable and performant RAT that demonstrates Rust’s viability as a premier language for offensive security development. It provided deep insights into low-level operating system interactions, advanced networking, and modern malware design principles. The final agent is lightweight, fast, and significantly more reliable than similar tools written in unsafe languages.

Developer Reflection

Building this RAT in Rust was an incredible learning experience. Rust forces you to think about ownership, memory, and concurrency from the start, which results in a far more robust final product. The performance is phenomenal, and the compiler catches so many potential security flaws before you even run the code. It’s clear why Rust is becoming the future for serious systems and security software.