Vectra Create Detection Alert for Hosts

Status: available
Severity: medium
Time window: 10m
Group by: entity_uid
Source: github.com/Azure/Azure-Sentinel

This analytic rule is looking for new attacker behaviors observed by the Vectra Platform. The intent is to create entries in the SecurityAlert table for every new detection attached to an entity monitored by the Vectra Platform

MITRE ATT&CK coverage

Tactic	Techniques
Persistence	`T1546` Event Triggered Execution

Rule body

id: fb861539-da19-4266-831f-99459b8e7605
name: Vectra Create Detection Alert for Hosts
version: 1.0.1
kind: Scheduled
description: This analytic rule is looking for new attacker behaviors observed by the Vectra Platform. The intent is to create entries in the SecurityAlert table for every new detection attached to an entity monitored by the Vectra Platform
status: Available
requiredDataConnectors:
  - connectorId: VectraXDR
    dataTypes:
      - Detections_Data_CL
severity: Medium
queryFrequency: 10m
queryPeriod: 10m
suppressionDuration: PT1H
suppressionEnabled: false
triggerOperator: GreaterThan
triggerThreshold: 0
tactics: 
  - Persistence
relevantTechniques:
  - T1546
query: |
  VectraDetections
  | where Type == "host"
  | extend
      entity_uid = ['Entity UID'],
      entity_id = ['Entity ID'],
      entity_type = ['Entity Type'],
      detection_id = ['Detection ID'],
      detection = ['Detection Name'],
      category = ['Detection Category'],
      detection_url = ['Vectra Pivot'],
      mitre = Mitre,
      tags = Tags
  | summarize arg_max(TimeGenerated, *) by ['Detection ID'], entity_uid
entityMappings:
- entityType: Host
  fieldMappings:
  - identifier: HostName
    columnName: entity_uid
incidentConfiguration:
  createIncident: false
  groupingConfiguration:
    enabled: false
    reopenClosedIncident: false
    lookbackDuration: PT5H
    matchingMethod: AllEntities
customDetails:
  entity_id: entity_id
  tags: tags
  entity_type: entity_type
  detection_id: detection_id
  mitre_techniques: mitre
alertDetailsOverride:
  alertDisplayNameFormat: Vectra AI Detection- {{detection}}
  alertDescriptionFormat: Vectra AI has detected {{category}} - {{detection}} on entity {{entity_uid}}.
  alertDynamicProperties:
  - alertProperty: AlertLink
    value: detection_url
eventGroupingSettings:
  aggregationKind: AlertPerResult

Stages and Predicates

Stage 1: `source`

VectraDetections

Stage 2: `where`

| where Type == "host"

Stage 3: `extend`

| extend
    entity_uid = ['Entity UID'],
    entity_id = ['Entity ID'],
    entity_type = ['Entity Type'],
    detection_id = ['Detection ID'],
    detection = ['Detection Name'],
    category = ['Detection Category'],
    detection_url = ['Vectra Pivot'],
    mitre = Mitre,
    tags = Tags

Stage 4: `summarize`

| summarize arg_max(TimeGenerated, *) by ['Detection ID'], entity_uid

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`Type`	eq	`host`	`field:"Type" kind:eq value:"host"`

Output fields

These fields are emitted when the rule matches.

Field	Source
`entity_uid`	`summarize`