incident-response

これはレビュー時に保存された抜粋です。完全で最新の内容は外部ソースを確認してください。

---
name: "incident-response"
description: "Use when a security incident has been detected or declared and needs classification, triage, escalation path determination, and forensic evidence collection. Covers SEV1-SEV4 classification, false positive filtering, incident taxonomy, and NIST SP 800-61 lifecycle."
---

# Incident Response

Incident response skill for the full lifecycle from initial triage through forensic collection, severity declaration, and escalation routing. This is NOT threat hunting (see threat-detection) or post-incident compliance mapping (see governance/compliance-mapping) — this is about classifying, triaging, and managing declared security incidents.

---

## Table of Contents

- [Overview](#overview)
- [Incident Triage Tool](#incident-triage-tool)
- [Incident Classification](#incident-classification)
- [Severity Framework](#severity-framework)
- [False Positive Filtering](#false-positive-filtering)
- [Forensic Evidence Collection](#forensic-evidence-collection)
- [Escalation Paths](#escalation-paths)
- [Regulatory Notification Obligations](#regulatory-notification-obligations)
- [Workflows](#workflows)
- [Anti-Patterns](#anti-patterns)
- [Cross-References](#cross-references)

---

## Overview

### What This Skill Does

This skill provides the methodology and tooling for **incident triage and response** — classifying security events into typed incidents, scoring severity, filtering false positives, determining escalation paths, and initiating forensic evidence collection under chain-of-custody controls.

### Distinction from Other Security Skills

| Skill | Focus | Approach |
|-------|-------|----------|
| **incident-response** (this) | Active incidents | Reactive — classify, escalate, collect evidence |
| threat-detection | Pre-incident hunting | Proactive — find threats before alerts fire |
| cloud-security | Cloud posture assessment | Preventive — IAM, S3, network misconfiguration |
| red-team | Offensive simulation | Offensive — test detection and response capability |

### Prerequisites

A security event must be ingested before triage. Events can come from SIEM alerts, EDR detections, threat intel feeds, or user reports. The triage tool accepts JSON event payloads; see the input schema below.

---

## Incident Triage Tool

The `incident_triage.py` tool classifies events, checks false positives, scores severity, determines escalation, and performs forensic pre-analysis.

```bash
# Classify an event from JSON file
python3 scripts/incident_triage.py --input event.json --classify --json

# Classify with false positive filtering enabled
python3 scripts/incident_triage.py --input event.json --classify --false-positive-check --json

# Force a severity level for tabletop exercises
python3 scripts/incident_triage.py --input event.json --severity sev1 --json

# Read event from stdin
echo '{"event_type": "ransomware", "host": "prod-db-01", "raw_payload": {}}' | \
  python3 scripts/incident_triage.py --classify --false-positive-check --json
```

### Input Event Schema

```json
{
  "event_type": "ransomware",
  "host": "prod-db-01",
  "user": "svc_backup",
  "source_ip": "10.1.2.3",
  "timestamp": "2024-01-15T14:32:00Z",
  "raw_payload": {}
}
```

### Exit Codes

| Code | Meaning | Required Response |
|------|---------|-------------------|
| 0 | SEV3/SEV4 or clean | Standard ticket-based handling |
| 1 | SEV2 — elevated | 1-hour bridge call, async coordination |
| 2 | SEV1 — critical | Immediate 15-minute war room, all-hands |

---

## Incident Classification

Security events are classified into 14 incident types. Classification drives default severity, MITRE technique mapping, and response SLA.

### Incident Taxonomy

| Incident Type | Default Severity | MITRE Technique | Response SLA |
|--------------|-----------------|-----------------|--------------|
| ransomware | SEV1 | T1486 | 15 minutes |
| data_exfiltration | SEV1 | T1048 | 15 minutes |
| apt_intrusion | SEV1 | T1566 | 15 minutes |
| supply_chain_compro