Cloudflare Quick Tunnels (*.trycloudflare.com) appear in the Kimsuky campaign (SCC-CAM-2026-0378) as a legitimate infrastructure layer abused for covert C2 communications. No Cloudflare software vulnerability is exploited; the risk is the free, zero-registration Quick Tunnel service being used as a disposable C2 relay that blends with legitimate Cloudflare tunnel traffic. The primary enterprise control is blocking or strictly controlling access to *.trycloudflare.com at the network perimeter.