Cobalt Strike's ExternalC2 framework vs Donut: Side-by-Side Comparison (2026)

Cobalt Strike's ExternalC2 framework

Red team operators and penetration testers who need to test defenses against custom C2 channels will use ExternalC2 to bypass network detection by routing Cobalt Strike traffic through external redirectors and custom protocols. The framework is free and lets you replace Cobalt Strike's default HTTP/HTTPS beaconing entirely, which means your C2 can blend into legitimate traffic patterns your client's sensors won't flag. Skip this if your team runs assessments using only default Cobalt Strike profiles or lacks the network infrastructure to host and manage external redirectors; the setup friction and operational complexity only pay off when you're specifically validating detection gaps around custom C2 communications.

Donut

Red teamers and penetration testers who need to deliver .NET and PE payloads that evade memory-scanning EDR will find Donut essential; it generates position-independent shellcode that executes directly from memory without touching disk, eliminating the most common detection vector. With 4,492 GitHub stars and active community contributions, the tool has been battle-tested across real engagements and stays current with Windows API changes. Skip this if you're looking for post-exploitation frameworks with built-in C2 capability or if your scope is limited to external reconnaissance; Donut is narrowly focused on the injection problem and assumes you already have payload delivery sorted.