Threat intelligence is the provision of evidence-based knowledge about existing or potential threats. Beneﬁts of threat
intelligence include improved efﬁciency and effectiveness in secu-rity operations in terms of detective and preventive capabilities.
Successful threat intelligence within the cyber domain demands a knowledge base of threat information and an expressive way
to represent this knowledge. This purpose is served by the use of taxonomies, sharing standards, and ontologies.
This paper introduces the Cyber Threat Intelligence (CTI) model, which enables cyber defenders to explore their threat
intelligence capabilities and understand their position against the ever-changing cyber threat landscape. In addition, we use
our model to analyze and evaluate several existing taxonomies, sharing standards, and ontologies relevant to cyber threat
intelligence. Our results show that the cyber security community lacks an ontology covering the complete spectrum of threat
intelligence. To conclude, we argue the importance of developing a multi-layered cyber threat intelligence ontology based on the
CTI model and the steps should be taken under consideration, which are the foundation of our future work.