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

Short answer

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. Penetration testers and bug bounty hunters doing reconnaissance will move faster with getallurls than manually querying individual URL sources; it aggregates results from CommonCrawl, URLScan, and Wayback Machine in a single pass. The tool has 4,549 GitHub stars and runs for free, making it a no-friction addition to any recon workflow. Skip this if you need real-time monitoring or filtered results; getallurls surfaces historical URLs without deduplication or relevance ranking, leaving you to sort signal from noise.