Alert deduplication - Learn about how Cortex XSIAM deduplicates alerts - Administrator Guide - Cortex XSIAM - Cortex - Security Operations

Cortex XSIAM Documentation

Product
Cortex XSIAM
Creation date
2024-03-06
Last date published
2026-05-31
Category
Administrator Guide
Abstract

Learn about how Cortex XSIAM deduplicates alerts

To optimize alert management and reduce noise, Cortex XSIAM employs a deduplication (dedup) mechanism for specific agent-based alerts.

What is deduplication?

Deduplication is the process of grouping identical security events that occur on the same endpoint within a specific timeframe. Instead of generating a new entry for every recurring instance of a threat, the system consolidates them into a single actionable alert.

Scope and conditions

Deduplication is strictly applied to alerts where the alert_name contains WildFire or Local Analysis. All other alert types are processed individually and will not be deduped.

The deduplication key

The system generates a unique fingerprint or key for each incoming alert. If the key matches an existing active alert within the timeframe, the new event is deduped. The formula is as follows:

{agent_id}_{alert_name}_{hash_id}_{action_status}_{name}_{trigger}

Key components are resolved using a specific fallback hierarchy to ensure a match even if some data is missing:

Component

Resolution Logic (Fallback Order)

hash_id

action_file_sha256 → action_process_image_sha256 → actor_process_image_sha256

name

action_file_name → action_process_image_name → actor_process_image_name

action_status

Appended only if alert_action_status is present (e.g., Blocked, Detected).

trigger

The prevention trigger value from messageData.trigger (if present).

Note

Alerts are automatically excluded from deduplication if the agent_id is missing, the hash_id is missing, or the hash_id is an all-zero SHA256 string.

Time-to-live (TTL)

The deduplication window is 1 hour. This is a sliding window that starts from the ingestion of the first alert. Identical events arriving within this 60-minute buffer are suppressed; events arriving after the window expires will trigger a new alert.

How to find deduplicated alerts

Deduplicated alerts are often referred to as "hidden" alerts because they do not appear as unique new rows in the alert table. Instead, they are aggregated into the initial "Parent" alert instance.

Locating suppressed events

To identify if an alert was suppressed by the dedup logic, search for the primary alert using the following criteria within a 1-hour window before the timestamp of the expected alert:

  • Agent ID: Match the specific agent_id of the endpoint.

  • Alert Name: Look for Local Analysis Malware or WildFire Malware.

  • File Identification (Hash): Use the SHA256 hierarchy (Action File → Action Process → Actor Process).

  • File/Process Name: Match the action_file_name or relevant process name.

  • Action Status: Ensure the alert_action_status matches (if it was present on the event).

If you find an alert matching these criteria that occurred less than 60 minutes prior, the "missing" alert has been successfully deduped into that existing entry.