In the broad domain of security, analysts and policymakers need knowledge about the state of the world to make timely critical decisions, operational/tactical as well as strategic. This knowledge has to be extracted from a variety of different sources and then represented in a form that will enable further analysis and decision making. Some of the data underlying this knowledge is in textual sources traditionally associated with Open-source Intelligence (OSINT). OSINT is intelligence gathered from publicly available overt sources such as newspapers, magazines, social networking sites, video sharing sites, wikis, blogs, etc. In the cybersecurity domain, information available through OSINT can complement data obtained through traditional security systems and monitoring tools like Intrusion Detection and Prevention Systems (IDPs). Cybersecurity information sources can be divided into two abstract groups, formal sources such as NIST’s National Vulnerability Database (NVD), United Sta...