Entity risk scoring

raw-migrated-files/docs-content/serverless/security-asset-criticality.md

@@ -117,7 +117,7 @@ Once you assign a criticality level to an entity, all subsequent alerts related
 
 ### Monitor an entity’s risk [security-asset-criticality-monitor-an-entitys-risk]
 
-The risk scoring engine dynamically factors in an entity’s asset criticality, along with `Open` and `Acknowledged` detection alerts to [calculate the entity’s overall risk score](../../../solutions/security/advanced-entity-analytics/entity-risk-scoring.md#security-entity-risk-scoring-how-is-risk-score-calculated). This dynamic risk scoring allows you to monitor changes in the risk profiles of your most sensitive entities, and quickly escalate high-risk threats.
+The risk scoring engine dynamically factors in an entity’s asset criticality, along with `Open` and `Acknowledged` detection alerts to [calculate the entity’s overall risk score](../../../solutions/security/advanced-entity-analytics/entity-risk-scoring.md#how-is-risk-score-calculated). This dynamic risk scoring allows you to monitor changes in the risk profiles of your most sensitive entities, and quickly escalate high-risk threats.
 
 To view the impact of asset criticality on an entity’s risk score, follow these steps:
 

raw-migrated-files/toc.yml

@@ -461,7 +461,6 @@ toc:
       - file: docs-content/serverless/security-endpoint-protection-intro.md
       - file: docs-content/serverless/security-endpoint-self-protection.md
       - file: docs-content/serverless/security-endpoints-page.md
-      - file: docs-content/serverless/security-entity-risk-scoring.md
       - file: docs-content/serverless/security-environment-variable-capture.md
       - file: docs-content/serverless/security-ers-requirements.md
       - file: docs-content/serverless/security-event-filters.md
@@ -860,7 +859,6 @@ toc:
       - file: security-docs/security/endpoint-protection-intro.md
       - file: security-docs/security/endpoint-protection-rules.md
       - file: security-docs/security/endpoint-self-protection.md
-      - file: security-docs/security/entity-risk-scoring.md
       - file: security-docs/security/environment-variable-capture.md
       - file: security-docs/security/ers-requirements.md
       - file: security-docs/security/es-overview.md

solutions/security/advanced-entity-analytics/entity-risk-scoring.md

@@ -4,17 +4,96 @@ mapped_urls:
   - https://www.elastic.co/guide/en/serverless/current/security-entity-risk-scoring.html
 ---
 
-# Entity risk scoring
+# Entity risk scoring [security-entity-risk-scoring]
 
-% What needs to be done: Lift-and-shift
+Entity risk scoring is an advanced {{elastic-sec}} analytics feature that helps security analysts detect changes in an entity’s risk posture, hunt for new threats, and prioritize incident response.
 
-% Use migrated content from existing pages that map to this page:
+Entity risk scoring allows you to monitor risk score changes of hosts and users in your environment. When generating advanced scoring analytics, the risk scoring engine utilizes threats from its end-to-end XDR use cases, such as SIEM, cloud, and endpoint. It leverages the Elastic SIEM detection engine to generate host and user risk scores from the last 30 days.
 
-% - [ ] ./raw-migrated-files/security-docs/security/entity-risk-scoring.md
-% - [ ] ./raw-migrated-files/docs-content/serverless/security-entity-risk-scoring.md
+It also generates risk scores on a recurring interval, and allows for easy onboarding and management. The engine is built to factor in risks from all {{elastic-sec}} use cases, and allows you to customize and control how and when risk is calculated.
 
-% Internal links rely on the following IDs being on this page (e.g. as a heading ID, paragraph ID, etc):
 
-$$$how-is-risk-score-calculated$$$
+## Risk scoring inputs [security-entity-risk-scoring-risk-scoring-inputs]
 
-$$$security-entity-risk-scoring-how-is-risk-score-calculated$$$
+Entity risk scores are determined by the following risk inputs:
+
+| Risk input | Storage location |
+| --- | --- |
+| [Alerts](../detect-and-alert/manage-detection-alerts.md) | `.alerts-security.alerts-<space-id>` index alias |
+| [Asset criticality level](asset-criticality.md) | `.asset-criticality.asset-criticality-<space-id>` index alias |
+
+The resulting entity risk scores are stored in the `risk-score.risk-score-<space-id>` data stream alias.
+
+::::{note}
+Entities without any alerts, or with only `Closed` alerts, are not assigned a risk score.
+
+::::
+
+
+
+## How is risk score calculated? [how-is-risk-score-calculated]
+
+1. The risk scoring engine runs hourly to aggregate `Open` and `Acknowledged` alerts from the last 30 days. For each entity, the engine processes up to 10,000 alerts.
+
+    ::::{note}
+    When [turning on the risk engine](turn-on-risk-scoring-engine.md), you can choose to also include `Closed` alerts in risk scoring calculations.
+    ::::
+
+2. The engine groups alerts by `host.name` or `user.name`, and aggregates the individual alert risk scores (`kibana.alert.risk_score`) such that alerts with higher risk scores contribute more than alerts with lower risk scores. The resulting aggregated risk score is assigned to the **Alerts** category in the entity’s [risk summary](../explore/hosts-page.md#security-hosts-overview-host-risk-summary).
+3. The engine then verifies the entity’s [asset criticality level](asset-criticality.md). If there is no asset criticality assigned, the entity risk score remains equal to the aggregated score from the **Alerts** category. If a criticality level is assigned, the engine updates the risk score based on the default risk weight for each criticality level. The asset criticality risk input is assigned to the **Asset Criticality** category in the entity’s risk summary.
+
+    | Asset criticality level | Default risk weight |
+    | --- | --- |
+    | Low impact | 0.5 |
+    | Medium impact | 1 |
+    | High impact | 1.5 |
+    | Extreme impact | 2 |
+
+    ::::{note}
+    Asset criticality levels and default risk weights are subject to change.
+
+    ::::
+
+4. Based on the two risk inputs, the risk scoring engine generates a single entity risk score of 0-100. It assigns a risk level by mapping the risk score to one of these levels:
+
+    | Risk level | Risk score |
+    | --- | --- |
+    | Unknown | < 20 |
+    | Low | 20-40 |
+    | Moderate | 40-70 |
+    | High | 70-90 |
+    | Critical | > 90 |
+
+
+::::{dropdown} Click for a risk score calculation example
+This example shows how the risk scoring engine calculates the user risk score for `User_A`, whose asset criticality level is **Extreme impact**.
+
+There are 5 open alerts associated with `User_A`:
+
+* Alert 1 with alert risk score 21
+* Alert 2 with alert risk score 45
+* Alert 3 with alert risk score 21
+* Alert 4 with alert risk score 70
+* Alert 5 with alert risk score 21
+
+To calculate the user risk score, the risk scoring engine:
+
+1. Sorts the associated alerts in descending order of alert risk score:
+
+    * Alert 4 with alert risk score 70
+    * Alert 2 with alert risk score 45
+    * Alert 1 with alert risk score 21
+    * Alert 3 with alert risk score 21
+    * Alert 5 with alert risk score 21
+
+2. Generates an aggregated risk score of 36.16, and assigns it to `User_A`'s **Alerts** risk category.
+3. Looks up `User_A`'s asset criticality level, and identifies it as **Extreme impact**.
+4. Generates a new risk input under the **Asset Criticality** risk category, with a risk contribution score of 16.95.
+5. Increases the user risk score to 53.11, and assigns `User_A` a **Moderate** user risk level.
+
+If `User_A` had no asset criticality level assigned, the user risk score would remain unchanged at 36.16.
+
+::::
+
+
+Learn how to [turn on the risk scoring engine](turn-on-risk-scoring-engine.md).