Modern Security Operations Centers (SOCs) face thousands of alerts daily β the majority false positives. AI transforms SOC efficiency through automated triage, ML-powered SIEM enrichment, and User & Entity Behavior Analytics (UEBA). In this lab you'll build a complete AI-driven SOC automation pipeline: from raw SIEM events through anomaly detection to MITRE ATT&CK-mapped playbook triggers.
Raw SIEM events contain unstructured logs. The first step normalizes them into feature vectors suitable for ML.
π‘ Feature Engineering for UEBA: The four key behavioral dimensions are time anomaly (login_time_hour), volume anomaly (bytes_transferred), authentication anomaly (failed_logins), and network anomaly (lateral_movement). IsolationForest treats these as a joint distribution.
Step 2: UEBA Model β IsolationForest Anomaly Detection
IsolationForest detects anomalies by measuring how easily a data point is isolated via random splits. Anomalies are isolated in fewer splits β lower (more negative) anomaly score.
πΈ Verified Output:
π‘ Score Interpretation: Scores below -0.5 indicate high confidence anomalies. User 98 (score=-0.82) shows the most extreme behavior: 23:00 login, 800KB exfiltration, 20 failed logins, lateral movement flag.
Step 3: Threat Scoring Model
Raw anomaly flags need a threat score (0β100) for analyst prioritization. Combine multiple signals:
Step 4: False Positive Reduction
Raw ML detections have false positives. Apply contextual filters and business rules:
π‘ FP Reduction Strategy: Layer your filters: whitelist β maintenance windows β peer group baseline β ML confidence threshold. Each layer reduces FP rate multiplicatively. Target: <1 false positive per analyst shift.
Step 5: MITRE ATT&CK Mapping
Map detected behaviors to ATT&CK tactics and techniques for structured incident response:
Step 6: Automated Playbook Execution
Map ATT&CK techniques to automated response playbooks:
Step 7: SOC Dashboard Metrics
Track SOC performance metrics for continuous improvement:
Step 8: Capstone β Full UEBA Pipeline
Run the complete end-to-end UEBA pipeline in Docker:
πΈ Verified Output:
All 5 injected anomalous users detected with 0 false positives. User 98 has the most extreme score (-0.82) reflecting simultaneous late-night access, 800KB exfil, 20 failed logins, and lateral movement β a textbook APT indicator.
Summary
Component
Technology
Purpose
UEBA Engine
IsolationForest
Unsupervised behavioral anomaly detection
Feature Space
4D behavioral vectors
Login time, bytes, failures, lateral movement
Threat Scoring
Composite 0β100
Prioritization for analyst queue
FP Reduction
Whitelist + peer group
Reduce alert fatigue
ATT&CK Mapping
MITRE ATT&CK v14
Structured technique classification
Playbook Automation
Rule-based engine
Auto-execute Tier-1 response actions
Alert Precision
~100% (clean data)
Maximize analyst efficiency
MTTD
< 5 minutes
AI vs. human hours
Key Takeaways:
IsolationForest scales to millions of events without labeled data
Composite threat scores outperform binary alerts for analyst prioritization