Shodan is a search engine that lets the user find specific types of computers connected to the internet using a variety of filters. Some have also described it as a search engine of service banners, which are metadata that the server sends back to the client. This can be information about the server software, what options the service supports, a welcome message or anything else that the client can find out before interacting with the server. Shodan collects data mostly on web servers, as well as FTP, SSH, Telnet, SNMP, IMAP, SMTP, SIP, and Real Time Streaming Protocol. The latter can be used to access webcams and their video stream. It was launched in 2009 by computer programmer John Matherly, who, in 2003, conceived the idea of searching devices linked to the Internet. The name Shodan is a reference to SHODAN, a character from the System Shock video game series.
Background
The website began as Matherly's pet project, based on the fact that large numbers of devices and computer systems are connected to the Internet. Shodan has since been used to find systems including control systems for water plants, power grids and a cyclotron.
Media coverage
In May 2013, CNN Money released an article detailing how Shodan can be used to find dangerous systems on the Internet, including traffic light controls. They show screenshots of those systems, which provided the warning banner "DEATH MAY OCCUR !!!" upon connecting. In September 2013, Shodan was referenced in a Forbes article claiming it was used in order to find the security flaws in TRENDnetsecurity cameras. The next day, Forbes followed up with a second article talking about the types of things that can be found using Shodan. This included Caterpillar trucks whose onboard monitoring systems were accessible, heating and security control systems for banks, universities, and corporate giants, surveillance cameras, and fetal heart monitors. In January 2015, Shodan was discussed in a CSO Online article addressing its pros and cons. According to one opinion, presented in the article as that of Hagai Bar-El, Shodan actually gives the public a good service, although it highlights vulnerable devices. This perspective is also described in one of his essays. In December 2015, various news outlets, including Ars Technica, reported that a security researcher used Shodan to identify accessible MongoDB databases on thousands of systems, including one hosted by Kromtech, the developer of the MacOS security tool MacKeeper.
Usage
The website crawls the Internet for publicly accessible devices, concentrating on SCADA systems. Shodan currently returns 10 results to users without an account and 50 to those with one. If users want to remove the restriction, they are required to provide a reason and pay a fee. The primary users of Shodan are cybersecurity professionals, researchers and law enforcement agencies. While cybercriminals can also use the website, some typically have access to botnets that could accomplish the same task without detection.
Popular culture
Shodan was featured on the American drama seriesMr. Robot in October 2017.