PortKnockr

PortKnockr is a lightweight external attack-surface scanner for small and mid-sized organizations that don’t have a mature security team. You point it at your domains and IP ranges; it continuously scans from multiple regions, fingerprints common services, flags risky exposures (RDP, SSH, admin panels, outdated TLS, open databases), and tracks changes over time. It’s not a full vulnerability scanner and it won’t replace a SIEM—trying to compete head-on with incumbents would be a mistake. Instead, it focuses on the boring, high-impact basics: “What is publicly reachable right now, and did it change since yesterday?” Alerts are designed for action, not noise: each finding includes a plain-English risk explanation, a suggested fix, and a verification re-scan. The product is a web app with an optional CLI for engineers to run on-demand checks in CI/CD.