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Vectra AI Detect - Suspected Compromised Host

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Id60eb6cf0-3fa1-44c1-b1fe-220fbee23d63
RulenameVectra AI Detect - Suspected Compromised Host
DescriptionCreate an incident when a Host is suspected to be compromised.

The higher the severity level is, the more immediate attention it requires as Vectra AI engine is more confident that this is a real threat.

Level of severity are: Low, Medium, High, Critical). Recommended configuration is to trigger an alert for at least High and Critical.
SeverityInformational
TacticsCredentialAccess
Discovery
LateralMovement
Collection
CommandAndControl
Exfiltration
Impact
Required data connectorsAIVectraDetect
AIVectraDetectAma
KindScheduled
Query frequency5m
Query period5m
Trigger threshold0
Trigger operatorgt
Source Urihttps://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Vectra AI Detect/Analytic Rules/VectraDetect-Host-by-Severity.yaml
Version1.0.6
Arm template60eb6cf0-3fa1-44c1-b1fe-220fbee23d63.json
Deploy To Azure
// Edit this variable to only keep the Severity level where an incident needs to be created (Defaults are: "High", "Critical" ). Possible values are: "Low", "Medium", "High", "Critical"
let configured_level = dynamic(["High", "Critical"]);
CommonSecurityLog
| where DeviceVendor == "Vectra Networks"
| where DeviceProduct == "X Series"
| where DeviceEventClassID == "hsc"
| project-rename threat_score = FlexNumber1
| project-rename certainty_score = FlexNumber2
| project-rename vectra_URL = DeviceCustomString4
| project-rename detection_name = DeviceEventClassID
| project-rename score_decreases = DeviceCustomString3
| extend level = case( threat_score <  50 and certainty_score < 50, "Low",
                      threat_score < 50 and certainty_score >= 50 , "Medium", 
                      threat_score >= 50 and certainty_score <= 50, "High", 
                      threat_score >= 50 and certainty_score >= 50, "Critical",
                      "UNKNOWN")
| extend Severity = case(level == "Info", "Informational",level == "Critical", "High", level)
| where level in (configured_level) 
//keep only the event with the highest threat score per Host
| summarize arg_max(TimeGenerated, *) by SourceHostName
| sort by TimeGenerated
alertDetailsOverride:
  alertSeverityColumnName: Severity
  alertDisplayNameFormat: Vectra AI Detect - Host {{SourceHostName}} reaches {{level}} severity
  alertDescriptionFormat: |
    The host {{SourceHostName}} has a Threat score of {{threat_score}} and a
    certainty of {{certainty_score}}    
  alertDynamicProperties:
  - alertProperty: AlertLink
    value: vectra_URL
  - alertProperty: ProductName
    value: DeviceProduct
  - alertProperty: ProviderName
    value: DeviceVendor
  - alertProperty: ConfidenceScore
    value: certainty_score
queryFrequency: 5m
tactics:
- CredentialAccess
- Discovery
- LateralMovement
- Collection
- CommandAndControl
- Exfiltration
- Impact
queryPeriod: 5m
kind: Scheduled
relevantTechniques: 
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Vectra AI Detect/Analytic Rules/VectraDetect-Host-by-Severity.yaml
eventGroupingSettings:
  aggregationKind: AlertPerResult
customDetails:
  ScoreDecrease: score_decreases
description: |
  'Create an incident when a Host is suspected to be compromised. 
  The higher the severity level is, the more immediate attention it requires as Vectra AI engine is more confident that this is a real threat. 
  Level of severity are: Low, Medium, High, Critical). Recommended configuration is to trigger an alert for at least High and Critical.'  
requiredDataConnectors:
- dataTypes:
  - CommonSecurityLog
  connectorId: AIVectraDetect
- dataTypes:
  - CommonSecurityLog
  connectorId: AIVectraDetectAma
version: 1.0.6
incidentConfiguration:
  createIncident: true
  groupingConfiguration:
    lookbackDuration: 7d
    matchingMethod: AllEntities
    reopenClosedIncident: true
    enabled: true
triggerThreshold: 0
severity: Informational
triggerOperator: gt
id: 60eb6cf0-3fa1-44c1-b1fe-220fbee23d63
entityMappings:
- entityType: Host
  fieldMappings:
  - columnName: SourceHostName
    identifier: HostName
status: Available
name: Vectra AI Detect - Suspected Compromised Host
query: |
  // Edit this variable to only keep the Severity level where an incident needs to be created (Defaults are: "High", "Critical" ). Possible values are: "Low", "Medium", "High", "Critical"
  let configured_level = dynamic(["High", "Critical"]);
  CommonSecurityLog
  | where DeviceVendor == "Vectra Networks"
  | where DeviceProduct == "X Series"
  | where DeviceEventClassID == "hsc"
  | project-rename threat_score = FlexNumber1
  | project-rename certainty_score = FlexNumber2
  | project-rename vectra_URL = DeviceCustomString4
  | project-rename detection_name = DeviceEventClassID
  | project-rename score_decreases = DeviceCustomString3
  | extend level = case( threat_score <  50 and certainty_score < 50, "Low",
                        threat_score < 50 and certainty_score >= 50 , "Medium", 
                        threat_score >= 50 and certainty_score <= 50, "High", 
                        threat_score >= 50 and certainty_score >= 50, "Critical",
                        "UNKNOWN")
  | extend Severity = case(level == "Info", "Informational",level == "Critical", "High", level)
  | where level in (configured_level) 
  //keep only the event with the highest threat score per Host
  | summarize arg_max(TimeGenerated, *) by SourceHostName
  | sort by TimeGenerated  
{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2023-02-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/60eb6cf0-3fa1-44c1-b1fe-220fbee23d63')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/60eb6cf0-3fa1-44c1-b1fe-220fbee23d63')]",
      "properties": {
        "alertDetailsOverride": {
          "alertDescriptionFormat": "The host {{SourceHostName}} has a Threat score of {{threat_score}} and a\ncertainty of {{certainty_score}}\n",
          "alertDisplayNameFormat": "Vectra AI Detect - Host {{SourceHostName}} reaches {{level}} severity",
          "alertDynamicProperties": [
            {
              "alertProperty": "AlertLink",
              "value": "vectra_URL"
            },
            {
              "alertProperty": "ProductName",
              "value": "DeviceProduct"
            },
            {
              "alertProperty": "ProviderName",
              "value": "DeviceVendor"
            },
            {
              "alertProperty": "ConfidenceScore",
              "value": "certainty_score"
            }
          ],
          "alertSeverityColumnName": "Severity"
        },
        "alertRuleTemplateName": "60eb6cf0-3fa1-44c1-b1fe-220fbee23d63",
        "customDetails": {
          "ScoreDecrease": "score_decreases"
        },
        "description": "'Create an incident when a Host is suspected to be compromised. \nThe higher the severity level is, the more immediate attention it requires as Vectra AI engine is more confident that this is a real threat. \nLevel of severity are: Low, Medium, High, Critical). Recommended configuration is to trigger an alert for at least High and Critical.'\n",
        "displayName": "Vectra AI Detect - Suspected Compromised Host",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "SourceHostName",
                "identifier": "HostName"
              }
            ]
          }
        ],
        "eventGroupingSettings": {
          "aggregationKind": "AlertPerResult"
        },
        "incidentConfiguration": {
          "createIncident": true,
          "groupingConfiguration": {
            "enabled": true,
            "lookbackDuration": "P7D",
            "matchingMethod": "AllEntities",
            "reopenClosedIncident": true
          }
        },
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Vectra AI Detect/Analytic Rules/VectraDetect-Host-by-Severity.yaml",
        "query": "// Edit this variable to only keep the Severity level where an incident needs to be created (Defaults are: \"High\", \"Critical\" ). Possible values are: \"Low\", \"Medium\", \"High\", \"Critical\"\nlet configured_level = dynamic([\"High\", \"Critical\"]);\nCommonSecurityLog\n| where DeviceVendor == \"Vectra Networks\"\n| where DeviceProduct == \"X Series\"\n| where DeviceEventClassID == \"hsc\"\n| project-rename threat_score = FlexNumber1\n| project-rename certainty_score = FlexNumber2\n| project-rename vectra_URL = DeviceCustomString4\n| project-rename detection_name = DeviceEventClassID\n| project-rename score_decreases = DeviceCustomString3\n| extend level = case( threat_score <  50 and certainty_score < 50, \"Low\",\n                      threat_score < 50 and certainty_score >= 50 , \"Medium\", \n                      threat_score >= 50 and certainty_score <= 50, \"High\", \n                      threat_score >= 50 and certainty_score >= 50, \"Critical\",\n                      \"UNKNOWN\")\n| extend Severity = case(level == \"Info\", \"Informational\",level == \"Critical\", \"High\", level)\n| where level in (configured_level) \n//keep only the event with the highest threat score per Host\n| summarize arg_max(TimeGenerated, *) by SourceHostName\n| sort by TimeGenerated\n",
        "queryFrequency": "PT5M",
        "queryPeriod": "PT5M",
        "severity": "Informational",
        "status": "Available",
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Collection",
          "CommandAndControl",
          "CredentialAccess",
          "Discovery",
          "Exfiltration",
          "Impact",
          "LateralMovement"
        ],
        "techniques": null,
        "templateVersion": "1.0.6",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}