07 incident response

Incident Response & Digital Forensics

Purpose

Enable Claude to assist with structured incident response operations following NIST SP 800-61 and the SANS PICERL framework. Claude generates IR playbooks, guides evidence collection with chain of custody, constructs forensic timelines, interprets memory forensics output, and produces post-incident reports.

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Activation Triggers

This skill activates when the user asks about:

• Creating an incident response playbook (ransomware, phishing, breach, etc.)
• Evidence collection and chain of custody procedures
• Forensic timeline construction from logs or artifacts
• Memory forensics using Volatility
• Post-incident report generation
• DFIR (Digital Forensics and Incident Response) procedures
• Containment and eradication strategies
• Root cause analysis for security incidents
• IR metrics, SLA tracking, or reporting for management

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Prerequisites

pip install pyyaml jinja2 pandas python-dateutil

Recommended DFIR tools:

• Volatility 3 — Memory forensics framework
• Autopsy / Sleuth Kit — Disk forensics
• plaso / log2timeline — Supertimeline generation
• KAPE — Evidence collection (Windows)
• Velociraptor — Enterprise-scale endpoint forensics
• FTK Imager — Forensic imaging (Windows)
• dd / dcfldd / dc3dd — Disk imaging (Linux)

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PICERL Framework Overview

Every IR engagement follows the PICERL lifecycle:

Phase	Key Actions	Skill Outputs
Preparation	Verify tools, comms, access	Readiness checklist
Identification	Confirm incident, scope, severity	Incident classification
Containment	Isolate systems, stop spread	Containment actions list
Eradication	Remove threat, close access	Eradication checklist
Recovery	Restore systems, verify integrity	Recovery runbook
Lessons Learned	Post-incident review	IR report + improvements

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Core Capabilities

1. IR Playbook Creation

When the user asks to create a playbook for a specific incident type:

Claude generates detailed, role-assigned playbooks in this structure:

Ransomware Response Playbook (Example):

# IR Playbook: Ransomware Attack
Version: 2.0 | Owner: SOC Manager | Review: Quarterly

## Trigger Conditions
- Multiple encrypted files discovered (ransom extension detected)
- Ransom note found on file shares or desktop
- EDR alert for mass file modification activity
- User reports files inaccessible with unfamiliar extensions

## Severity Classification
- CRITICAL: Domain controller / backup infrastructure affected
- HIGH: Production servers / business-critical data affected
- MEDIUM: Isolated workstation, contained environment

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## Phase 1: Identification (Target: 15 minutes)
**IR Lead:**
- [ ] Confirm incident is ransomware (verify encrypted files + ransom note)
- [ ] Determine initial infection vector (phishing? RDP? Supply chain?)
- [ ] Identify Patient Zero — first encrypted system
- [ ] Assess scope: How many systems? Which business units?
- [ ] Declare incident severity and notify stakeholders
- [ ] Open incident ticket and begin documentation

**Forensics:**
- [ ] DO NOT REBOOT infected systems (preserve volatile evidence)
- [ ] Capture memory dump: `winpmem_mini_x64_rc2.exe output.raw`
- [ ] Collect running processes: `tasklist /v > processes.txt`
- [ ] Collect network connections: `netstat -ano > netstat.txt`

## Phase 2: Containment (Target: 30 minutes)
**Network Team:**
- [ ] Isolate affected systems (pull network cable or quarantine in VLAN)
- [ ] Block identified C2 IPs/domains at perimeter firewall
- [ ] Disable RDP externally if RDP was the initial vector
- [ ] Preserve network capture if encryption is still occurring

**Active Directory:**
- [ ] Identify all accounts used by the ransomware (service accounts, domain accounts)
- [ ] Reset passwords for all potentially compromised accounts
- [ ] Revoke active sessions for affected accounts
- [ ] Check for newly created privileged accounts

## Phase 3: Eradication
- [ ] Identify all persistence mechanisms (registry, services, scheduled tasks)
- [ ] Remove all malicious artifacts
- [ ] Verify no backdoors remain (check with Autoruns, process scanning)
- [ ] Patch the exploited vulnerability if one was used

## Phase 4: Recovery
- [ ] Restore from clean backup (verified pre-infection)
- [ ] Validate backup integrity before restoration
- [ ] Rebuild from gold image if backup compromised
- [ ] Verify data integrity after restoration
- [ ] Phased return to production

## Phase 5: Lessons Learned (Within 2 weeks)
- [ ] Full incident timeline documented
- [ ] Root cause identified and remediated
- [ ] Detection gaps addressed
- [ ] CSOC playbook updated
- [ ] Management report delivered

Other supported playbook types:

• Phishing Campaign Response
• Data Breach / Exfiltration
• Business Email Compromise (BEC)
• Insider Threat
• DDoS Attack
• Account Compromise / Credential Stuffing
• Supply Chain Compromise
• Cloud Misconfiguration / Breach

2. Evidence Collection & Chain of Custody

When the user asks to collect forensic evidence:

Order of Volatility (most volatile → least volatile):

1. CPU registers and cache
2. Routing tables, ARP cache, process table
3. Memory (RAM) — ALWAYS capture first
4. Temporary file systems, swap space
5. Running processes and open files
6. Network connections and open ports
7. Disk images
8. Log files (local + remote SIEM)
9. Physical media

Evidence Collection Commands:

# Windows — Live acquisition
winpmem_mini_x64_rc2.exe memory.raw              # Memory dump
tasklist /svc > processes.txt                     # Running processes
netstat -ano > connections.txt                    # Network connections
wmic process get caption,processid,parentprocessid,commandline > process_full.txt
reg export HKLM reg_hklm.reg                     # Registry
dir /s /a "C:\Users\*\AppData\Roaming\*" > appdata.txt

# Linux — Live acquisition
sudo avml /tmp/memory.lime                        # Memory dump (avml)
ps auxf > processes.txt                           # Process tree
netstat -tulnap > connections.txt                 # Network connections
cat /proc/*/cmdline | strings > process_cmdlines.txt
ls -la /tmp/ /var/tmp/ /dev/shm/ > temp_dirs.txt
crontab -l -u root > crontabs.txt
find / -mtime -7 -type f > recently_modified.txt  # Modified in last 7 days

Chain of Custody Template:

## Evidence Chain of Custody Form

| Field | Value |
|-------|-------|
| Evidence ID | IR-2025-001-E01 |
| Incident ID | IR-2025-001 |
| Description | Memory dump from HOSTNAME (192.168.1.100) |
| Collected by | [Analyst Name] |
| Collection time | 2025-05-28 14:30 UTC |
| Collection method | winpmem_mini_x64_rc2.exe |
| MD5 hash | [hash of evidence file] |
| SHA256 hash | [hash of evidence file] |
| Storage location | \nas\ir\IR-2025-001\evidence\ |
| Chain of custody | Analyst → Evidence Locker → Lab |

**Access Log:**
| Date/Time | Person | Purpose | Signature |
|-----------|--------|---------|-----------|
| 2025-05-28 14:30 | [Analyst] | Initial collection | [Sig] |

3. Forensic Timeline Analysis

When the user asks to build an incident timeline:

1. Collect timestamps from all available sources:

   • Windows Event Logs (Security, System, Application, PowerShell)
   • Web server access logs
   • Firewall / proxy logs
   • Email server logs (delivery, read receipts)
   • File system timestamps (Modified, Accessed, Changed, Born)
   • Registry LastWrite timestamps
   • Prefetch timestamps (evidence of execution)

2. Normalize to UTC — Confirm system timezone before conversion

3. Generate supertimeline:

   python scripts/timeline_builder.py --logs ./collected_logs/ --output timeline.csv
   python scripts/timeline_builder.py --logs ./logs/ --format html --start "2025-05-20" --end "2025-05-28"
   

4. Identify the kill chain progression:

## Incident Timeline — [Incident ID]

[T-72h] 2025-05-25 09:15 UTC — DELIVERY
  Phishing email received: "Invoice_May2025.pdf.exe" from spoofed sender
  Mail log: SMTP delivery to [email protected] from 185.x.x.x

[T-48h] 2025-05-26 14:22 UTC — EXECUTION
  User executed attachment: Event 4688 (process creation)
  Parent: outlook.exe → Child: powershell.exe -enc [base64]

[T-48h] 2025-05-26 14:22 UTC — C2 ESTABLISHED
  Outbound connection: 203.x.x.x:443 (beacon_interval: 60s)
  DNS query: malicious-c2.evil.com → 203.x.x.x

[T-24h] 2025-05-27 02:00 UTC — LATERAL MOVEMENT
  PsExec from WORKSTATION01 to SERVER02 (admin$)
  Event 4624 (login type 3) on SERVER02 from WORKSTATION01

[T-2h]  2025-05-27 12:30 UTC — DATA EXFILTRATION
  Large POST request (450MB) to dropbox-like service

[T-0h]  2025-05-28 14:00 UTC — DETECTION
  SOC analyst detected anomalous outbound transfer

4. Memory Forensics

When the user shares Volatility output or asks about memory forensics:

Essential Volatility 3 Commands:

# Process listing
python vol.py -f memory.raw windows.pslist
python vol.py -f memory.raw windows.pstree           # Show parent-child
python vol.py -f memory.raw windows.psscan           # Find hidden processes

# Network connections
python vol.py -f memory.raw windows.netscan
python vol.py -f memory.raw windows.netstat

# DLL and module analysis
python vol.py -f memory.raw windows.dlllist --pid [PID]
python vol.py -f memory.raw windows.modscan          # All loaded modules

# Malware detection
python vol.py -f memory.raw windows.malfind           # Injected code
python vol.py -f memory.raw windows.hollowfind        # Process hollowing

# Registry from memory
python vol.py -f memory.raw windows.registry.hivelist
python vol.py -f memory.raw windows.registry.printkey --key "SOFTWARE\Microsoft\Windows\CurrentVersion\Run"

# File artifacts
python vol.py -f memory.raw windows.filescan
python vol.py -f memory.raw windows.dumpfiles --physaddr [addr]

Suspicious Memory Indicators:

• Process without corresponding disk file (process hollowing)
• explorer.exe or svchost.exe with unusual parent
• Network connections from system processes (lsass.exe, csrss.exe)
• Executable memory regions flagged by windows.malfind
• Stacked THREADS in injected shellcode regions

5. Post-Incident Report

When the user asks for an IR report for management or compliance:

# Post-Incident Report — [Incident ID]

**Classification:** CONFIDENTIAL
**Incident Type:** [Ransomware / Data Breach / etc.]
**Severity:** [Critical / High / Medium]
**Incident Window:** [Start] to [End] UTC
**Systems Affected:** [Count and names]
**Data Impact:** [Data at risk / confirmed exfiltrated]
**Report Date:** [Date]
**Report Author:** [IR Lead]

---

## 1. Executive Summary
[3-4 sentences: what happened, how it happened, impact, and current status]

## 2. Incident Timeline
[Key events table with timestamps]

## 3. Root Cause Analysis
**Initial Vector:** [Phishing / Unpatched service / Credential theft / etc.]
**Root Cause:** [Specific technical cause]
**Contributing Factors:**
- [Factor 1: e.g., no MFA on VPN]
- [Factor 2: e.g., delayed patch deployment]

## 4. Impact Assessment
- **Systems Compromised:** [List]
- **Data Accessed/Exfiltrated:** [Description + quantity]
- **Business Impact:** [Downtime hours, revenue impact, regulatory]
- **Customer/Partner Impact:** [If applicable]

## 5. Containment & Remediation Actions
[Chronological list of actions taken]

## 6. Compliance Notification Requirements
- **GDPR:** [Required if EU personal data — 72-hour notification to DPA]
- **HIPAA:** [Required if PHI — notify HHS within 60 days]
- **PCI-DSS:** [Required if cardholder data — notify card brands immediately]
- **State breach laws:** [Applicable laws and timelines]

## 7. Recommendations
| Priority | Recommendation | Owner | Due Date |
|----------|---------------|-------|---------|
| Critical | Deploy MFA for all remote access | IT | 2025-06-01 |
| High | Accelerate patch cycle for internet-facing systems | IT | 2025-06-15 |
| Medium | Implement email attachment sandboxing | Security | 2025-07-01 |

## 8. Lessons Learned
[What worked, what didn't, process improvements]

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Script Reference

timeline_builder.py

python scripts/timeline_builder.py --logs ./collected_logs/ --output timeline.csv
python scripts/timeline_builder.py --logs ./logs/ --format html --start "2025-05-20" --end "2025-05-28"

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Skill Integration

Condition	Adjacent Skill
Alert received from SOC → activate IR	← Skill 11 (CSOC Automation)
Malware samples collected → analyze	→ Skill 05 (Malware Analysis)
IOCs extracted → hunt in environment	→ Skill 06 (Threat Hunting)
Log deep-dive needed	→ Skill 12 (Log Analysis)

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References

• NIST SP 800-61 Rev. 2 — Computer Security Incident Handling
• SANS Incident Response Process
• Volatility 3 Documentation
• Velociraptor Documentation
• DFIR.training Resource Hub
• The Art of Memory Forensics (Book)

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v3.0 Enhancements (2026 Update)

Cloud- and identity-era IR:

• Cloud IR — pull and triage AWS CloudTrail, Azure Activity/Entra sign-in & audit, and GCP Audit logs; preserve volatile cloud state (snapshots, IAM key disabling) before remediation.
• Identity & SaaS compromise — handle token theft/replay, OAuth consent abuse, and federated trust attacks; revoke sessions/refresh tokens, rotate signing keys, review conditional-access.
• Modern toolkit — Velociraptor for fleet-scale collection; Hayabusa/Chainsaw + Sigma over EVTX for rapid Windows timelining; KAPE for triage images.
• Ransomware specifics — identify double/triple-extortion, exfil-before-encrypt evidence, ESXi/Linux scope, and recovery validation against immutable backups.
• Business Email Compromise — inbox-rule and forwarding abuse, app-password persistence, mailbox audit log review.

Process rule (unchanged priority): follow NIST SP 800-61 / SANS PICERL; preserve chain of custody; in cloud/OT contexts weigh evidence preservation against service/safety continuity (→ Skill 18 for OT).