analyzing-threat-intelligence-feeds

name	analyzing-threat-intelligence-feeds
description	Analyzes structured and unstructured threat intelligence feeds to extract actionable indicators, adversary tactics, and campaign context. Use when ingesting commercial or open-source CTI feeds, evaluating feed quality, normalizing data into STIX 2.1 format, or enriching existing IOCs with campaign attribution. Activates for requests involving ThreatConnect, Recorded Future, Mandiant Advantage, MISP, AlienVault OTX, or automated feed aggregation pipelines.
domain	cybersecurity
subdomain	threat-intelligence
tags	["STIX","TAXII","MITRE-ATT&CK","IOC","ThreatConnect","Recorded-Future","MISP","CTI","NIST-CSF"]
version	1.0.0
author	mahipal
license	Apache-2.0
nist_csf	["ID.RA-01","ID.RA-05","DE.CM-01","DE.AE-02"]
mitre_attack	["T1071.001","T1566","T1568","T1583.001","T1102"]
source	https://github.com/mukul975/Anthropic-Cybersecurity-Skills
source_commit	04450304b12645cb2b974ab96d28c0664758a88d

Analyzing Threat Intelligence Feeds

When to Use

Use this skill when:

• Ingesting new commercial or OSINT threat feeds and assessing their signal-to-noise ratio
• Normalizing heterogeneous IOC formats (STIX 2.1, OpenIOC, YARA, Sigma) into a unified schema
• Evaluating feed freshness, fidelity, and relevance to the organization's threat profile
• Building automated enrichment pipelines that correlate IOCs against SIEM events

Do not use this skill for raw packet capture analysis or live incident triage without first establishing a CTI baseline.

Prerequisites

• Access to a Threat Intelligence Platform (TIP) such as ThreatConnect, MISP, or OpenCTI
• API keys for at least one commercial feed (Recorded Future, Mandiant Advantage, or VirusTotal Enterprise)
• TAXII 2.1 client library (taxii2-client Python package or equivalent)
• Role with read/write permissions to the TIP's indicator database

Workflow

Step 1: Enumerate and Prioritize Feed Sources

List all available feeds categorized by type (commercial, government, ISAC, OSINT):

• Commercial: Recorded Future, Mandiant Advantage, CrowdStrike Falcon Intelligence
• Government: CISA AIS (Automated Indicator Sharing), FBI InfraGard, MS-ISAC
• OSINT: AlienVault OTX, Abuse.ch, PhishTank, Emerging Threats

Score each feed on: update frequency, historical accuracy rate, coverage of your sector, and attribution depth. Use a weighted scoring matrix with criteria from NIST SP 800-150 (Guide to Cyber Threat Information Sharing).

Step 2: Ingest via TAXII 2.1 or API

For TAXII-enabled feeds:

taxii2-client discover https://feed.example.com/taxii/
taxii2-client get-collection --collection-id <id> --since 2024-01-01

For REST API feeds (e.g., Recorded Future):

• Query /v2/indicator/search with risk_score_min=65 to filter low-confidence IOCs
• Apply rate limiting and exponential backoff for API resilience

Step 3: Normalize to STIX 2.1

Convert each IOC to STIX 2.1 objects using the OASIS standard schema:

• IP address → indicator object with pattern: "[ipv4-addr:value = '...']"
• Domain → indicator with pattern: "[domain-name:value = '...']"
• File hash → indicator with pattern: "[file:hashes.SHA-256 = '...']"