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Introduction
Incident response is a structured approach to addressing and managing security breaches, whether in traditional IT or industrial control systems (ICS/OT). While the core phases remain the same, the execution differs due to the unique challenges in OT environments. This article breaks down the six critical phases of incident response, providing actionable insights and technical guidance for cybersecurity professionals.
Learning Objectives
- Understand the six phases of incident response in IT and OT/ICS environments.
- Learn key technical commands and steps for effective incident containment and eradication.
- Identify best practices for post-incident recovery and lessons learned.
1. Preparation
Key Command: Log Review with `journalctl` (Linux)
journalctl -u sshd --since "1 hour ago"
What it does:
This command checks SSH login attempts in the last hour, helping identify unauthorized access.
Step-by-Step Guide:
- Run the command in a terminal with root privileges.
- Look for failed login attempts (
Failed passwordentries).
3. Cross-reference IPs with threat intelligence feeds.
Why it matters:
Proactive log monitoring helps detect early signs of compromise before an incident escalates.
2. Identification
Key Command: Network Traffic Analysis with `tcpdump` (Linux)
tcpdump -i eth0 -w ot_traffic.pcap
What it does:
Captures network traffic on interface `eth0` and saves it to a file for analysis.
Step-by-Step Guide:
1. Run the command to start packet capture.
2. Use Wireshark or `tshark` to analyze `ot_traffic.pcap`.
- Look for unusual connections (e.g., unexpected external IPs).
Why it matters:
OT networks often lack robust monitoring, making packet capture critical for identifying malicious activity.
3. Containment
Key Command: Isolate a Compromised Host (Windows)
Stop-Service -Name "WinRM" -Force
What it does:
Disables Windows Remote Management to prevent lateral movement.
Step-by-Step Guide:
1. Open PowerShell as Administrator.
2. Run the command to stop the service.
3. Verify with `Get-Service WinRM`.
Why it matters:
Quickly cutting off attacker access limits damage in both IT and OT environments.
4. Eradication
Key Command: Reset All Passwords (Linux/Windows)
chage -l <user> Check password expiry passwd <user> Force password reset
What it does:
Ensures compromised credentials are invalidated.
Step-by-Step Guide:
- List all users with `cat /etc/passwd` (Linux) or `net user` (Windows).
2. Reset passwords for each account.
3. Enforce multi-factor authentication (MFA) where possible.
Why it matters:
Password resets are a baseline step to eliminate persistent attacker access.
5. Recovery
Key Command: Restore from Backup (Linux)
rsync -avz /backup/ /opt/application/
What it does:
Syncs a clean backup to restore critical systems.
Step-by-Step Guide:
1. Validate backup integrity with checksums.
- Use `rsync` or Windows Backup to restore files.
3. Test functionality before returning to production.
Why it matters:
OT systems often rely on legacy applications; backups ensure minimal downtime.
6. Lessons Learned
Key Command: Generate Incident Report (Linux)
cat /var/log/syslog | grep "FAILED" > incident_report.txt
What it does:
Extracts failed login attempts for post-mortem analysis.
Step-by-Step Guide:
1. Aggregate logs from all affected systems.
2. Document timelines, actions taken, and gaps.
3. Update IR playbooks based on findings.
Why it matters:
Continuous improvement reduces future incident response times.
What Undercode Say
- Key Takeaway 1: OT/IR requires cross-functional collaboration—engineers and operators must be involved early.
- Key Takeaway 2: Proactive preparation (e.g., tabletop exercises) significantly reduces incident impact.
Analysis:
While IT and OT incident response share phases, OT’s operational constraints (e.g., uptime requirements) demand tailored strategies. For example, disconnecting an OT system may require manual overrides, unlike IT’s automated isolations. Future attacks will increasingly target OT, making IR preparedness non-negotiable for critical infrastructure.
Prediction
As OT/ICS systems become more interconnected, attackers will exploit legacy protocols (e.g., Modbus) for ransomware and espionage. Organizations must adopt zero-trust architectures and real-time monitoring to mitigate these evolving threats.
IT/Security Reporter URL:
Reported By: Mikeholcomb The – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
