operationalizing-misp-threat-feeds

Imported from mukul975/anthropic-cybersecurity-skills (skills/operationalizing-misp-threat-feeds/SKILL.md). Install upstream with npx skills add mukul975/anthropic-cybersecurity-skills --skill operationalizing-misp-threat-feeds. Copyright stays with the author (Apache-2.0).

Operationalizing MISP Threat Feeds

Note: This skill covers a defensive threat-intelligence platform. Handle ingested intelligence according to its Traffic Light Protocol (TLP) marking and your sharing agreements. Treat ingested IOCs as potentially sensitive.

Overview

MISP (Malware Information Sharing Platform) is the de-facto open-source threat-intelligence platform for storing, correlating, and sharing structured indicators (IOCs), events, galaxies (threat-actor/technique knowledge), and objects. Running a MISP instance is only the first step; the value comes from operationalizing it — curating high-quality feeds, suppressing false positives with warninglists, and pushing the resulting IOCs into detection tooling so intelligence actually drives blocking and alerting.

A feed in MISP is a remote source (another MISP, a CSV/freetext list, or a structured collection) that you enable and optionally cache. Caching pulls the feed's IOCs into the instance's Redis-backed cache so values can be correlated and looked up in real time (e.g., a SIEM asking "have you seen this domain?") without importing every event. Curation matters: enabling every public feed produces noise and false positives, so you select reputable feeds (CIRCL OSINT, abuse.ch, Feodo Tracker, etc.), apply warninglists (known-good ranges like RFC1918, Alexa/Tranco top sites, public DNS resolvers) to flag non-actionable indicators, and use taxonomies/tags (TLP, confidence) to scope what gets exported.

The detection-engineering payoff comes from MISP's export formats and PyMISP. MISP can render matching attributes directly as Suricata and Snort rules via the REST API, and PyMISP lets you script extraction of fresh IOCs to generate Sigma rules and Wazuh CDB lists / rules on a schedule. This skill walks the full lifecycle: feed enablement and caching, warninglist-based FP reduction, PyMISP-driven search, and automated generation of Suricata, Sigma, and Wazuh detections.

When to Use

• Standing up or maturing a MISP instance into a feed that drives detection, not just a repository.
• Curating and caching public/commercial threat feeds with quality controls.
• Reducing IOC false positives with warninglists before they reach the SIEM/IDS.
• Automating generation of Suricata/Sigma/Wazuh detections from MISP attributes.
• Integrating MISP with a SOC so DNS/IP/hash lookups can be enriched against current intel.

Prerequisites

• A running MISP instance (the maintained container images are the fastest path):

  git clone https://github.com/MISP/misp-docker.git
  cd misp-docker && cp template.env .env
  docker compose up -d
  # Web UI on https://localhost; default admin: admin@admin.test / admin

• A MISP Auth Key (UI: Administration -> List Auth Keys -> Add).
• PyMISP:

  pip install pymisp

• Target detection tooling reachable: Suricata, a Sigma toolchain (pip install sigma-cli), and/or Wazuh manager.

Objectives

• Enable and cache curated threat feeds in MISP.
• Apply warninglists to suppress known-good / non-actionable indicators.
• Authenticate and query MISP with PyMISP to pull fresh, scoped IOCs.
• Export matching attributes as Suricata/Snort rules via the REST API.
• Generate Sigma rules and Wazuh CDB lists from MISP attributes on a schedule.
• Validate that generated detections load and fire in the target tooling.

MITRE ATT&CK Mapping

Workflow

1. Add and enable a feed

Register a reputable source and turn it on.

# add_feed.py (PyMISP) — register the CIRCL OSINT feed
from pymisp import PyMISP, MISPFeed
misp = PyMISP("https://localhost", "YOUR_AUTH_KEY", ssl=False)
feed = MISPFeed()
feed.name = "CIRCL OSINT Feed"
feed.provider = "CIRCL"
feed.url = "https://www.circl.lu/doc/misp/feed-osint"
feed.source_format = "misp"
feed.input_source = "network"
feed.enabled = True
print(misp.add_feed(feed, pythonify=True))

2. Cache enabled feeds for real-time correlation

Caching loads feed IOCs into Redis so lookups are instant.

# Cache all enabled feeds (equivalent to "Enable caching" in the UI)
print(misp.cache_all_feeds())
# Or fetch a single feed's events into the instance by feed id:
print(misp.fetch_feed(1))

3. Enable warninglists to reduce false positives

Turn on known-good lists so non-actionable indicators are flagged.

# Enable the common false-positive warninglists
for wl in misp.warninglists(pythonify=True):
    if wl.name in ("List of RFC 1918 CIDR blocks",
                   "Top 1000 website from Cisco Umbrella",
                   "List of known public DNS resolvers"):
        misp.toggle_warninglist(warninglist_id=wl.id, force_enable=True)

4. Authenticate and search for fresh IOCs

Pull recently published, TLP-scoped, to-IDS attributes only.

from pymisp import PyMISP
misp = PyMISP("https://localhost", "YOUR_AUTH_KEY", ssl=False)
# Only export attributes flagged to_ids=1, published, last 7 days, IP/domain/url/hash
attrs = misp.search(
    controller="attributes",
    type_attribute=["ip-dst", "domain", "url", "md5", "sha256"],
    to_ids=True, published=True, last="7d",
    enforce_warninglist=True,   # drop warninglisted (known-good) values
    pythonify=True,
)
print(f"{len(attrs)} actionable IOCs")

5. Export Suricata/Snort rules via the REST API

MISP renders matching attributes directly as IDS rules.

# Suricata rules for all to_ids network IOCs (NIDS export)
curl -s -k -H "Authorization: YOUR_AUTH_KEY" -H "Accept: application/json" \
  "https://localhost/attributes/restSearch/returnFormat:suricata/to_ids:1/type:domain%7Cip-dst%7Curl" \
  -o misp_suricata.rules

# Snort equivalent
curl -s -k -H "Authorization: YOUR_AUTH_KEY" -H "Accept: application/json" \
  "https://localhost/attributes/restSearch/returnFormat:snort/to_ids:1" -o misp_snort.rules

6. Deploy the Suricata rules

Load and reload.

cp misp_suricata.rules /etc/suricata/rules/
suricata -T -c /etc/suricata/suricata.yaml   # validate config + rules
suricatasc -c reload-rules                    # hot reload

7. Generate Wazuh CDB lists from IOCs

Convert MISP domains/IPs into a Wazuh CDB lookup list referenced by a rule.

# Build a Wazuh CDB list (key:value per line) from the searched attributes
with open("misp_iocs.cdb", "w") as fh:
    for a in attrs:
        if a.type in ("domain", "ip-dst"):
            fh.write(f"{a.value}:\n")
# On the Wazuh manager: place under /var/ossec/etc/lists/, reference in ossec.conf:
#   <list>etc/lists/misp_iocs</list>
# then compile and restart:
#   /var/ossec/bin/wazuh-control restart

8. Generate Sigma rules from MISP intelligence

Emit a Sigma rule matching the exported domains.

import yaml
domains = [a.value for a in attrs if a.type == "domain"]
sigma = {
    "title": "MISP feed malicious domain contact",
    "status": "experimental",
    "logsource": {"category": "dns"},
    "detection": {"selection": {"query|contains": domains}, "condition": "selection"},
    "level": "high",
    "tags": ["attack.command_and_control", "attack.t1071.004"],
}
with open("misp_domains.yml", "w") as fh:
    yaml.safe_dump(sigma, fh, sort_keys=False)

9. Convert and deploy Sigma to your SIEM backend

Use sigma-cli to compile to the target backend (Splunk, Elastic, etc.).

sigma convert -t splunk -p splunk_windows misp_domains.yml > misp_domains.spl
sigma convert -t elasticsearch misp_domains.yml > misp_domains.eql

10. Schedule the pipeline and run the bundled helper

agent.py searches MISP and writes Suricata/Sigma/Wazuh artifacts in one pass; schedule it via cron.

python scripts/agent.py --url https://localhost --key YOUR_AUTH_KEY \
  --last 7d --outdir ./detections --insecure
# crontab: 0 * * * * /usr/bin/python /path/scripts/agent.py ... >> /var/log/misp_pipeline.log 2>&1

Tools and Resources

Validation Criteria

• MISP instance reachable and an Auth Key created.
• At least one reputable feed enabled and cached.
• Relevant warninglists enabled and enforce_warninglist applied to searches.
• PyMISP search returns scoped, to_ids, non-warninglisted IOCs.
• Suricata/Snort rules exported via REST and validated with suricata -T.
• Wazuh CDB list generated and loaded by the manager.
• Sigma rule generated and converted to the SIEM backend.
• Generated detections confirmed to load (and fire on a test IOC).
• Pipeline scheduled and logging successfully.