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Properly classifying incidents is essential for accurate reporting, tuning detection rules, and understanding your security posture. This guide explains when to use each classification type.

Classification vs Status

Before diving into classifications, it’s important to understand the difference between Status and Classification:

Status

Work state of the investigation
  • New — Not yet reviewed
  • Active — Under investigation
  • Closed — Investigation complete

Classification

Outcome of the investigation
  • True Positive
  • False Positive
  • Benign Positive
  • Undetermined
Status tracks where you are in the investigation process. Classification documents what you found when the investigation is complete.

Classification Types

True Positive

True Positive

The incident represents an actual security threat that required response.
When to use:
  • Confirmed malicious activity was detected
  • A real attack or compromise occurred
  • Threat actor activity was identified
  • Malware, phishing, or unauthorized access was verified
Examples:
  • User credentials were actually compromised
  • Malware was confirmed running on an endpoint
  • Data exfiltration attempt was verified
  • Unauthorized access to sensitive resources occurred
True Positives validate that your detection rules are working correctly. Document the threat details in comments for future reference.

Benign Positive

Benign Positive

The detection was technically correct, but the activity was legitimate and authorized.
When to use:
  • Suspicious-looking activity was actually authorized
  • A user performed unusual but legitimate actions
  • IT/Admin activities triggered security alerts
  • Penetration testing or security assessments caused alerts
Examples:
  • Admin legitimately accessed multiple systems during maintenance
  • User traveled and logged in from an unusual location
  • Authorized penetration test triggered alerts
  • New software deployment caused unusual process behavior
Benign Positives help identify opportunities for tuning. Consider creating exceptions or adjusting detection thresholds for known legitimate activities.

False Positive

False Positive

The incident was incorrectly triggered due to flawed detection logic or bad data.
When to use:
  • Detection rule logic is flawed or too broad
  • Inaccurate or corrupted data triggered the alert
  • Misconfiguration caused incorrect detection
  • The alert has no basis in actual activity
False Positive classification reasons
Sub-classifications:
ReasonDescription
Inaccurate dataThe data used to generate the alert was incorrect, incomplete, or corrupted
Incorrect alert logicThe detection rule itself is flawed and needs to be modified or disabled
Examples:
  • Alert triggered on a non-existent user due to log parsing error
  • Detection rule matches normal business activity too broadly
  • Time zone misconfiguration caused false temporal correlation
  • Deprecated system generated alerts for decommissioned resources
False Positives indicate detection problems that should be addressed. Report patterns of False Positives to improve detection quality.

Undetermined

Undetermined

The investigation was inconclusive—the cause or outcome couldn’t be determined.
When to use:
  • Insufficient evidence to reach a conclusion
  • Logs or data needed for investigation are unavailable
  • The incident doesn’t fit other classification categories
  • Investigation was abandoned due to resource constraints
Examples:
  • Relevant logs expired before investigation completed
  • Activity was suspicious but couldn’t be verified either way
  • Source system was decommissioned, preventing further analysis
  • Alert context was insufficient for determination
When using Undetermined, always add detailed comments documenting what was discovered during the investigation. This helps if the incident needs to be revisited later.

Quick Reference

ClassificationMeaningAction
True PositiveReal threat confirmedDocument threat details, validate response actions
Benign PositiveCorrect detection, authorized activityConsider tuning or adding exceptions
False PositiveIncorrect detectionReport for rule improvement
UndeterminedInconclusive investigationDocument findings in comments

Classification Decision Tree

Use this flow to determine the correct classification:

Best Practices

Document your investigation findings regardless of classification. This creates an audit trail and helps with future investigations of similar incidents.
Work with your team to establish classification guidelines. Consistent classification improves metrics accuracy and detection tuning.
Regularly review classification trends. High False Positive rates indicate detection rules that need tuning. High Benign Positive rates suggest exception lists need updating.
Use Undetermined only when you genuinely cannot determine the outcome. Overuse of Undetermined reduces the value of your classification data.


Questions about classifications? Contact us at [email protected].