Intelligence Sharing

Why Share?

Intelligence sharing creates a network effect — threats identified by one organisation protect the entire community. However, sharing must be governed, reciprocal, and risk-managed.

Sharing Models

1. ISACs (Information Sharing and Analysis Centers)

Sector-specific sharing communities.

Benefits: Sector-relevant intelligence, trusted community, pre-vetted members, established TLP norms.

2. FIRST (Forum of Incident Response and Security Teams)

Global incident response community. Membership-based, includes national CERTs and enterprise security teams.

Sharing via: FIRST mailing lists, TF-CSIRT community, CTI SIG.

3. MISP (Malware Information Sharing Platform)

Open-source threat intelligence platform for sharing IOCs and threat data.

How to share via MISP:

1. Create an event with appropriate distribution
2. Add attributes (IOCs) with correct types
3. Tag with TLP, ATT&CK techniques, and galaxies
4. Set distribution: Organisation only / Community / Connected communities / All
5. Publish event

4. STIX/TAXII (Automated Sharing)

Standards for structured intelligence exchange.

• STIX 2.1: Format for representing intelligence (see stix-bundle skill)
• TAXII 2.1: Transport protocol for exchanging STIX bundles

TAXII channels:

• Collections: Server-hosted repositories of STIX objects
• Channels: Push-based distribution
• API roots: Discovery endpoints

5. Bilateral/Multilateral Sharing

Direct sharing with trusted partners under agreed terms.

Requirements:

• Sharing agreement (legal framework)
• TLP adherence by both parties
• Secure communication channel
• Reciprocity expectation

TLP and Sharing

What to Share

Do Share

• IOCs from confirmed incidents (with context)
• TTPs observed in your environment
• Detection rules that work
• Vulnerability intelligence relevant to sector
• Anonymised incident lessons learned

Don't Share

• Source-identifying information without source consent
• Victim-identifying information without victim consent
• Raw internal telemetry or logs
• Information that reveals your security posture
• Speculation presented as intelligence

Sharing Quality

Shared intelligence should meet the same quality standards as internal products:

• Source assessment (Admiralty Scale)
• Confidence levels
• MITRE ATT&CK mapping
• Proper TLP marking
• Context (not just raw IOCs — explain what they mean)

The number one complaint about shared intelligence: "Just IOCs with no context." Always share the WHY alongside the WHAT.

Legal Considerations

• Comply with data protection regulations (GDPR, sector-specific rules)
• Ensure sharing agreements cover liability
• TLP is a trust agreement, not a legal framework — complement with contracts
• Be aware of export control regulations for certain technical intelligence
• Document all sharing decisions for audit trail