shodan

Shodan operates as a massive, distributed scanning engine that continuously probes the public internet to identify and catalog connected devices, including servers, IoT hardware, and industrial control systems. By capturing banners and metadata from open ports, it creates a searchable database that allows security professionals to track the exposure of specific technologies or services. It is widely considered the industry standard for internet-wide reconnaissance and security posture assessment.

Shodan crawls the web to map the digital footprint of the internet, helping users understand what devices are exposed and potentially vulnerable. The data collected is used to power their search engine, which allows security researchers to identify misconfigured systems or track the spread of specific software versions. Operators can verify the traffic by checking if the source IP belongs to Shodan's known scanning infrastructure or by reviewing their official documentation on how to opt-out of their indexing.