# Cobalt Strike's ExternalC2 framework

Cobalt Strike's ExternalC2 framework is a Red-Team & Adversary Emulation product. It runs on-premises. Pricing is free.

A specification/framework for extending default C2 communication channels in Cobalt Strike

Checked October 2026.

## What is Cobalt Strike's ExternalC2 framework?

ExternalC2 is a specification/framework introduced by Cobalt Strike, which allows hackers to extend the default HTTP(S)/DNS/SMB C2 communication channels offered. Essentially this works by allowing the user to develop a number of components: Third-Party Controller - Responsible for creating a connection to the Cobalt Strike TeamServer, and communicating with a Third-Party Client on the target host using a custom C2 channel. Third-Party Client - Responsible for communicating with the Third-Party Controller using a custom C2 channel, and relaying commands to the SMB Beacon. SMB Beacon - The standard beacon which will be executed on the victim host.

Using the diagram from CS’s documentation, we can see just how this all fits together.

Tags: C2

## 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
- Website: blog.xpnsec.com

## Cobalt Strike's ExternalC2 framework FAQ

### What is Cobalt Strike's ExternalC2 framework?

Cobalt Strike's ExternalC2 framework is a product in the Red-Team & Adversary Emulation category. It covers C2.

### What is the pricing for Cobalt Strike's ExternalC2 framework?

Cobalt Strike's ExternalC2 framework is free. Download and setup instructions are at https://blog.xpnsec.com/exploring-cobalt-strikes-externalc2-framework/.

### What are alternatives to Cobalt Strike's ExternalC2 framework?

Alternatives to Cobalt Strike's ExternalC2 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. [Trickest Attack Surface Management](https://cybersectools.com/tools/trickest-attack-surface-management) - Platform for offensive security operations including ASM, VA, and DAST (Commercial)
5. [GoSecure Titan® Adversarial Simulation](https://cybersectools.com/tools/gosecure-titanr-adversarial-simulation) - Human-led adversary emulation service testing detection & response capabilities (Commercial)

Compare all Cobalt Strike's ExternalC2 framework alternatives at [https://cybersectools.com/alternatives/cobalt-strikes-externalc2-framework](https://cybersectools.com/alternatives/cobalt-strikes-externalc2-framework)

### What deployment and organization size does Cobalt Strike's ExternalC2 framework fit?

Cobalt Strike's ExternalC2 framework is available as on-premises software. It is listed for enterprises. It is free.

## Compare Cobalt Strike's ExternalC2 framework with similar solutions

- [Cobalt Strike's ExternalC2 framework vs Fortra Cobalt Strike](https://cybersectools.com/compare/cobalt-strikes-externalc2-framework-vs-fortra-cobalt-strike)
- [Cobalt Strike's ExternalC2 framework vs Core Security Cobalt Strike](https://cybersectools.com/compare/cobalt-strikes-externalc2-framework-vs-core-security-cobalt-strike)
- [Cobalt Strike's ExternalC2 framework vs Dreadnode Offensive Security Agents](https://cybersectools.com/compare/cobalt-strikes-externalc2-framework-vs-dreadnode-offensive-security-agents)

All alternatives to Cobalt Strike's ExternalC2 framework: [/alternatives/cobalt-strikes-externalc2-framework](https://cybersectools.com/alternatives/cobalt-strikes-externalc2-framework)

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

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More on Cobalt Strike's ExternalC2 framework: funding, momentum, hiring and news, plus the full product and company record, are available through the Mandos MCP Server (paid plans), which connects to AI assistants: https://mandos.io/mcp?utm_source=cybersectools.com&utm_medium=product-md