A search engine for finding Internet-connected devices. Shodan lets technicians find out how many computers are running particular software such as a type of Web server or which version of some software is most popular. It can also identify how many IP addresses in a country are vulnerable to a particular exploit.
Shodan can be accessed from its www.shodan.io website, through a command line interface as well as a programming interface (API) for several languages.
Shodan collects text snippets, known as "banners," which describe the type of service, and each banner is different. For example, the banner for a Web server looks very different than the banner for an industrial control system. Banners also include the location, hostname and OS.
Same Crawling Process
In the same bots crawl the Web all day long for website information, Shodan crawls the Internet in a random manner looking for connected hosts and services. It has crawlers in the U.S., China, France, Iceland, Taiwan, Romania and the Czech Republic.
How Many Apache Servers Are There?
On January 22, 2020, this was the result of a Shodan search of Apache Web servers running.