Speed is the
Only Defense.
Ransomware spreads faster than you can type. How to build a SOAR playbook that detects and contains threats at machine speed.
The average "breakout time" (time it takes for an adversary to move laterally) is dropping every year.
If your analysts are manually investigating every alert, you have already lost.
SOAR (Security Orchestration, Automation, and Response) allows us to codify our
response procedures.
1. The Logic App Architecture
We use Azure Logic Apps, triggered by a Microsoft Sentinel Incident.
The Workflow:
1. Trigger: Sentinel creates an incident with tag
"Malware".
2. Get Entity: Logic App extracts the Hostname and IP.
3. Enrich: Query VirusTotal API for reputation.
4. Action: If Severity > High, call Microsoft Defender
for Endpoint API to "Isolate Device".
5. Notify: Send Adaptive Card to Teams channel for
analyst visibility.
// JSON Definition (Snippet)
"actions": {
"Isolate_Machine": {
"type": "Http",
"method": "POST",
"uri": "https://api.securitycenter.microsoft.com/..."
"body": { "Comment": "Automated Isolation via LogicApp" }
}
}
2. Results
By automating Tier-1 containment, we reduced Mean Time To Remediate (MTTR) from 4 hours to 30
seconds.
This frees up analysts to do what they do best: Threat Hunting and Root Cause Analysis.
3. Architecture Deep Dive
Automation isn't just about scripts; it's about reliability and error handling. A production-grade playbook must utilize:
- Managed Identity: Never store secrets in your Logic App. Use System Assigned Identities.
- Parallel Branches: Execute enrichment actions (IP rep, User risk) simultaneously to save time.
- Error Scopes: Use Try-Catch patterns to alert engineers if the playbook fails.
- Human-in-the-Loop: For destructive actions (e.g., Delete User), always require an approval email step.
Conclusion
The future of SOC is not more analysts; it's smarter workflows. By automating the routine, we empower our team to focus on the novel and the sophisticated.