Individual skill

hunting-for-domain-fronting-c2-traffic

Detect domain fronting C2 traffic by analyzing SNI vs HTTP Host header mismatches in proxy logs and TLS certificate discrepancies using pyOpenSSL for certificate inspection

internal/tools/skills/data/threat-hunting/hunting-for-domain-fronting-c2-traffic/SKILL.md

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Observed behavior: Network or broad shell
Last checked: Nov 9, 2026

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Repository stars (not skill ratings): 1,317
Repository last updated: Nov 8, 2026
License: Apache-2.0

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cybersecurity Repository topic
security Repository topic
bug-bounty Repository topic
automation Repository topic
autonomous-pentesting Repository topic
ai-agent Repository topic
ai-security Repository topic
ethical-hacking Repository topic
golang Repository topic
penetration-testing Repository topic
domain-fronting Declared skill tag
c2-detection Declared skill tag
tls-inspection Declared skill tag
proxy-logs Declared skill tag
pyopenssl Declared skill tag
threat-hunting Declared skill tag
network-security Declared skill tag
security Derived category

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# Hunting for Domain Fronting C2 Traffic

## Overview

Domain fronting (MITRE ATT&CK T1090.004) is a technique where attackers use different domain names in the TLS SNI field and the HTTP Host header to disguise C2 traffic behind legitimate CDN-hosted domains. This skill detects domain fronting by parsing proxy/web gateway logs for SNI-Host header mismatches, analyzing TLS certificates for CDN provider identification, flagging connections where the SNI points to a high-reputation domain but the Host header targets an attacker-controlled domain, and correlating with known CDN provider IP ranges.


## When to Use

- When investigating security incidents that require hunting for domain fronting c2 traffic
- When building detection rules or threat hunting queries for this domain
- When SOC analysts need structured procedures for this analysis type
- When validating security monitoring coverage for related attack techniques