# external_c2 framework

external_c2 framework is a Red-Team & Adversary Emulation product. It runs on-premises. Pricing is free.

A Python framework for building custom Command and Control interfaces that implements Cobalt Strike's External C2 specification for data transfer between frameworks.

Checked October 2026.

## What is external_c2 framework?

A Python framework designed for building and utilizing interfaces to transfer data between frameworks, with specific focus on extending Command and Control (C2) capabilities. The framework implements Cobalt Strike's External C2 specification, allowing users to create custom communication channels and data transfer mechanisms.

The framework consists of several core components including a builder system that reads configuration files and generates builds by replacing markers within code skeletons. The builder functionality is accessible through build_files.py and uses sample configuration files to customize the build process.

The architecture includes skeletons which serve as code templates containing markers that are dynamically populated with usable values during the build process. Additional components include frameworks, transports, and encoders that work together to facilitate data transfer operations.

The project builds upon and extends Outflank's External C2 project, providing enhanced capabilities for implementing custom C2 communication protocols and interfaces. The framework is designed to be extensible and may evolve to support additional C2 specifications beyond Cobalt Strike as the project develops.

Tags: C2, Red Team, Exploitation Framework

## Quick facts

- Category: [Offensive Security](https://cybersectools.com/categories/offensive-security-testing) · [Red-Team & Adversary Emulation](https://cybersectools.com/categories/offensive-security)
- Deployment: On-Premises
- Company size fit: Enterprise
- Pricing model: Free
- GitHub stars: 241
- Website: github.com

## external_c2 framework FAQ

### What is external_c2 framework?

external_c2 framework is a product in the Red-Team & Adversary Emulation category. It covers C2, Red Team and Exploitation Framework.

### What is the pricing for external_c2 framework?

external_c2 framework is free. Download and setup instructions are at https://github.com/Und3rf10w/external_c2_framework/.

### What are alternatives to external_c2 framework?

Alternatives to external_c2 framework listed on CybersecTools:

1. [Fortra Cobalt Strike](https://cybersectools.com/tools/fortra-cobalt-strike) - Threat emulation product for adversary simulations and red team operations (Commercial)
2. [Core Security Cobalt Strike](https://cybersectools.com/tools/core-security-cobalt-strike) - Post-exploitation threat emulation platform for red team operations. (Commercial)
3. [Dreadnode Offensive Security Agents](https://cybersectools.com/tools/dreadnode-offensive-security-agents) - AI agent platform for automating offensive security operations and evals. (Commercial)
4. [Red Specter Cheatsheet](https://cybersectools.com/tools/red-specter-cheatsheet) - CLI cheatsheet for Red Specter's 30-tool offensive security platform. (Commercial)
5. [KinoSec Hades](https://cybersectools.com/tools/kinosec-hades) - Autonomous AI offensive cyber platform for sovereign-grade threat neutralization. (Commercial)

Compare all external_c2 framework alternatives at [https://cybersectools.com/alternatives/externalc2-framework](https://cybersectools.com/alternatives/externalc2-framework)

### What deployment and organization size does external_c2 framework fit?

external_c2 framework is available as on-premises software. It is listed for enterprises. It is free.

## Compare external_c2 framework with similar solutions

- [external_c2 framework vs Fortra Cobalt Strike](https://cybersectools.com/compare/externalc2-framework-vs-fortra-cobalt-strike)
- [external_c2 framework vs Core Security Cobalt Strike](https://cybersectools.com/compare/core-security-cobalt-strike-vs-externalc2-framework)
- [external_c2 framework vs Dreadnode Offensive Security Agents](https://cybersectools.com/compare/dreadnode-offensive-security-agents-vs-externalc2-framework)

All alternatives to external_c2 framework: [/alternatives/externalc2-framework](https://cybersectools.com/alternatives/externalc2-framework)

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Source: https://cybersectools.com/tools/externalc2-framework

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