Heartbleed vulnerability was uncovered in April 2014, revealing a serious vulnerability in OpenSSL. The vulnerability could have helped hackers steal information such as passwords. The map was tweeted by John Matherly, the founder of Shodan, a search engine for the internet of things. Shodan searches for the technical characteristics of devices attached to the net, including devices that are likely to be ignored by search engines. IT teams can use tools like Shodan to help them check their companys security, testing with filters to determine if web servers are running a particular version of Apache.”]
Source: https://grahamcluley.com/heartbleed-200000-vulnerable-devices-internet/