A candidate ontology is the Stucco Ontology. Stucco is an open source cyber intelligence platform. The Stucco ontology identifies 15 entity types:
- User
- Account
- Host
- Address
- IP
- Address Range
- Port
- Service
- Domain Name
- Software
- Vulnerability
- flow
- Malware
- Attack
- Attacker
See Developing an Ontology for Cyber Security Knowledge Graphs.