This repository defines the Open Cybersecurity Schema Framework (OCSF) schema. OCSF is a framework for creating schemas and it also delivers a cybersecurity event schema built with the framework.

The framework is made up of a set of categories, event classes, data types, and an attribute dictionary. The framework is not restricted to cybersecurity nor to events, however the initial focus of the framework has been a schema for cybersecurity events. A schema browser for the cybersecurity schema can be found at schema.ocsf.io. This is the recommended way to explore the schema.

OCSF is agnostic to storage format, data collection and ETL processes. The core schema for cybersecurity events is intended to be agnostic to implementations. The schema framework definition files and the resulting schema are written as JSON.

OCSF is intended to be used by both products and devices which produce log events, analytic systems, and logging systems which retain log events.

Extensions are additional categories, event classes, attributes, objects or profiles. The Open Cybersecurity Schema Framework can be extended by adding new attributes, objects, categories and event classes. A schema is the aggregation of core schema entities and extensions. Extensions allow a particular vendor or customer to create a new schema or augment an existing schema. Extensions can also be used to factor out non-essential schema domains keeping a schema small. Extensions use the framework in the same way as a new schema, optionally creating categories, profiles or event classes from the dictionary. Extensions can add new attributes to the dictionary, including new objects. As with categories, event classes and profiles, extensions have unique IDs within the framework as well as versioning.

To extend the schema create a new directory in the schema/extensions directory. The directory structure is the same as the top level schema directory, and it may contain the following files and subdirectories.

For more information on extending the schema, please refer to the contribution guide, CONTRIBUTING.md

Updates to OCSF follow semantic versioning.

This software is licensed under the Apache License, version 2 ("ALv2").