Performing Alert Triage With Elastic Siem

Performing Alert Triage with Elastic SIEM

Overview

Alert triage in Elastic Security is the systematic process of reviewing, classifying, and prioritizing security alerts to determine which represent genuine threats. Elastic's AI-driven Attack Discovery feature can triage hundreds of alerts down to discrete attack chains, but skilled analyst triage remains essential. A structured triage workflow typically takes 5-10 minutes per alert cluster using Elastic's built-in tools.

When to Use

Trigger phrases:

• "performing alert triage with elastic siem"

• "Perform systematic alert triage in Elastic Security SIEM to rapidly classify, pr"

• When conducting security assessments that involve performing alert triage with elastic siem

• When following incident response procedures for related security events

• When performing scheduled security testing or auditing activities

• When validating security controls through hands-on testing

Prerequisites

• Elastic Security deployed (version 8.x or later)
• Elastic Agent or Beats configured for endpoint and network data collection
• Detection rules enabled and generating alerts
• Elastic Common Schema (ECS) compliance across data sources
• Analyst access to Kibana Security app with appropriate privileges

Alert Triage Workflow

1. Scope the task — define objectives, boundaries, and success criteria
2. Gather information — collect all necessary data and context before proceeding
3. Execute the core workflow — follow the domain-specific steps methodically
4. Validate results — verify outputs against expected outcomes or baselines
5. Document findings — record results, anomalies, and recommendations

Step 1: Initial Alert Assessment (2 minutes)

When viewing an alert in Elastic Security, review the alert details panel:

Alert Details Panel:
- Rule Name and Description
- Severity and Risk Score
- MITRE ATT&CK Mapping
- Host and User Context
- Process Tree (for endpoint alerts)
- Timeline of related events

Key Fields to Examine First

Step 2: Context Gathering (3 minutes)

Query Related Events with ES|QL

FROM logs-endpoint.events.*
| WHERE host.name == "affected-host" AND @timestamp > NOW() - 1 HOUR
| STATS count = COUNT(*) BY event.category, event.action
| SORT count DESC

Find All Activity from Suspicious User

FROM logs-*
| WHERE user.name == "suspicious-user" AND @timestamp > NOW() - 24 HOURS
| STATS count = COUNT(*), unique_hosts = COUNT_DISTINCT(host.name) BY event.category
| SORT count DESC

Check for Related Alerts from Same Source

FROM .alerts-security.alerts-default
| WHERE source.ip == "10.0.0.50" AND @timestamp > NOW() - 24 HOURS
| STATS alert_count = COUNT(*) BY kibana.alert.rule.name, kibana.alert.severity
| SORT alert_count DESC

Investigate Lateral Movement from Same IP

FROM logs-system.auth-*
| WHERE source.ip == "10.0.0.50" AND event.outcome == "success"
| STATS login_count = COUNT(*), hosts = COUNT_DISTINCT(host.name) BY user.name
| WHERE hosts > 3

Step 3: Threat Intelligence Enrichment (2 minutes)

Check indicators against threat intelligence:

FROM logs-ti_*
| WHERE threat.indicator.ip == "203.0.113.50"
| KEEP threat.indicator.type, threat.indicator.provider, threat.indicator.confidence, threat.feed.name

Check File Hash Against Known Threats

FROM logs-endpoint.events.file-*
| WHERE file.hash.sha256 == "abc123..."
| STATS occurrences = COUNT(*) BY host.name, file.path, user.name

Step 4: Classification Decision (2 minutes)

Step 5: Documentation and Escalation (1 minute)

For each triaged alert, document:

• Classification decision with rationale
• Evidence artifacts examined
• Related alerts or investigations
• Recommended next steps

Detection Rules for Triage

This section covers detection rules for triage for performing alert triage with elastic siem.

• Ensure all prerequisites are met before proceeding
• Follow the documented workflow steps in sequence
• Record results and any anomalies encountered during this phase

Pre-Built Detection Rules

Elastic Security includes 1000+ pre-built detection rules organized by:

• MITRE ATT&CK Tactic: Initial Access, Execution, Persistence, etc.
• Platform: Windows, Linux, macOS, Cloud
• Data Source: Endpoint, Network, Cloud, Identity

Custom Alert Correlation Rule

{
  "name": "Multiple Failed Logins Followed by Success",
  "type": "threshold",
  "query": "event.category:authentication AND event.outcome:failure",
  "threshold": {
    "field": ["source.ip", "user.name"],
    "value": 5,
    "cardinality": [
      {
        "field": "user.name",
        "value": 3
      }
    ]
  },
  "severity": "high",
  "risk_score": 73,
  "threat": [
    {
      "framework": "MITRE ATT&CK",
      "tactic": {
        "id": "TA0006",
        "name": "Credential Access"
      },
      "technique": [
        {
          "id": "T1110",
          "name": "Brute Force"
        }
      ]
    }
  ]
}

AI-Assisted Triage

This section covers ai-assisted triage for performing alert triage with elastic siem.

• Ensure all prerequisites are met before proceeding
• Follow the documented workflow steps in sequence
• Record results and any anomalies encountered during this phase

Elastic AI Assistant Integration

1. Open alert in Elastic Security
2. Click AI Assistant panel
3. Use quick prompts:
   • "Summarize this alert" - Get initial assessment
   • "Generate ES|QL query to find related activity" - Expand investigation
   • "What are the recommended response actions?" - Get playbook guidance
   • "Is this likely a false positive?" - Get AI confidence assessment

Attack Discovery

Elastic's Attack Discovery automatically:

• Groups related alerts into attack chains
• Maps alerts to MITRE ATT&CK kill chain stages
• Filters false positives using ML models
• Prioritizes based on business impact
• Provides narrative summary of the attack

Triage Prioritization Matrix

Triage Metrics and KPIs

When NOT to Use

• You don't have explicit written authorization to test
• Task is about defense/detection, not offense (use detection skills)
• You need to implement security controls (use implementing-* skills)
• Task requires compliance auditing (use auditing-* skills)
• You're investigating an incident (use incident response skills)
• Target is out of scope for your engagement
• Task is about vulnerability scanning only (use scanning tools)

Red Flags

• Performing actions without explicit written authorization from the asset owner
• Testing against production systems without a defined scope and rules of engagement
• Destroying potential evidence during the containment phase
• Failing to document the chain of custody for all collected artifacts
• Communicating incident details over unencrypted or monitored channels

Verification

• All steps executed successfully against a test environment before production use
• Output documented with screenshots or logs demonstrating expected behavior
• Timeline of events reconstructed with corroborating evidence
• Root cause identified and documented with contributing factors
• Post-incident review completed with lessons learned and action items

References

• Elastic Security - Triage Alerts Documentation
• SOC Analyst's Guide to Triage with Elastic
• Elastic Blog - AI and 2025 SIEM Landscape
• Reducing False Positives with Elastic and Tines

Process

1. Analyze the task requirements
2. Apply domain expertise
3. Verify output quality

Anti-Rationalization Table