Agent skill

understanding-ocsf

Understand the OCSF schema. Use when working with OCSF, looking up classes or objects, normalizing security events, or asking about the schema.

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Forks 31

Install this agent skill to your Project

npx add-skill https://github.com/majiayu000/claude-skill-registry/tree/main/skills/security/understanding-ocsf-tenzir-claude-plugins

SKILL.md

Understanding OCSF

The Open Cybersecurity Schema Framework (OCSF) is a vendor-agnostic schema for normalizing security telemetry. This skill helps you understand its structure.

Core Concepts

OCSF organizes cybersecurity data through five interconnected constructs:

  1. Attributes - Named data types (scalar or complex) that form the foundation. See attributes.md.

  2. Objects - Collections of contextually related attributes representing entities like Process, User, or File. See objects.md.

  3. Classes - Structured sets of attributes and objects describing specific security events like authentication or file activity. See classes.md.

  4. Profiles - Dynamic mix-ins that augment classes with cross-cutting attributes (e.g., Cloud, Container, Host). See profiles.md.

  5. Extensions - Mechanisms for expanding the schema without modifying the core. See extensions.md.

Hierarchy

Attributes  →  Objects  →  Event Classes  →  Categories
   │              │              │               │
   └──────────────┴──────────────┴───────────────┘
                  compose into
  • Attributes populate Objects
  • Objects populate Event Classes
  • Event Classes are organized into Categories
  • Profiles cross-cut multiple Event Classes
  • Extensions can add new elements at any level

Categories

OCSF organizes event classes into 8 categories:

Category UID Use When
System 1xxx OS/endpoint events (files, processes)
Findings 2xxx Security detections and alerts
IAM 3xxx Identity and access (auth, account changes)
Network 4xxx Network communication (connections, DNS)
Discovery 5xxx Asset/config state (inventory, software)
Application 6xxx Application behavior (API, datastore)
Remediation 7xxx Incident response activities
Unmanned 8xxx Unmanned systems (experimental)

Quick Reference

Version-specific References

Detailed per-class and per-object references: references/

If references/index.md is missing, run the generator script:

sh
uv run scripts/generate-references.py

To generate docs for a specific version:

sh
uv run scripts/generate-references.py --version 1.3.0

External Resources

Deep-dives and FAQs are available from the OCSF docs repository. Fetch the raw content when relevant. Base URL: https://raw.githubusercontent.com/ocsf/ocsf-docs/main/

Articles

File Fetch When
articles/profiles-are-powerful.md Profile modeling approaches (augmentation, native, hybrid)
articles/defining-and-using-observables.md Enriching events with observables for querying
articles/representing-process-parentage.md Process parent/creator relationships in endpoint events
articles/patching-core-using-extensions.md Adding attributes to core schema without new classes
articles/modeling-alerts.md Using is_alert attribute, Detection Finding vs Security Control

FAQs

File Fetch When
faqs/schema-faq.md Creating events, required attributes, profiles, Actor object, observables, naming conventions, versioning

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