TI map URL entity to SecurityAlert data

let dt_lookBack = 1h;
let ioc_lookBack = 14d;
ThreatIntelligenceIndicator
| where TimeGenerated >= ago(ioc_lookBack) and ExpirationDateTime > now()
| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
| where Active == true
// Picking up only IOC's that contain the entities we want
| where isnotempty(Url)
// using innerunique to keep perf fast and result set low, we only need one match to indicate potential malicious activity that needs to be investigated
| join kind=innerunique (
  SecurityAlert
  | where TimeGenerated >= ago(dt_lookBack)
  | extend MSTI = case(AlertName has "TI map" and VendorName == "Microsoft" and ProductName == 'Azure Sentinel', true, false)
  | where MSTI == false
  // Extract URL from JSON data
  | extend Url = extract("(http[s]?://(?:[a-zA-Z]|[0-9]|[$-_@.&+]|[!*\\(\\),]|(?:%[0-9a-fA-F][0-9a-fA-F]))+)", 1,Entities)
  // We only want alerts that actually contain URL data
  | where isnotempty(Url)
  // Extract hostname from JSON data for entity mapping
  | extend Compromised_Host = tostring(parse_json(ExtendedProperties).["Compromised Host"])
  | extend Alert_TimeGenerated = TimeGenerated
) on Url
| where Alert_TimeGenerated < ExpirationDateTime
| summarize Alert_TimeGenerated = arg_max(Alert_TimeGenerated, *) by IndicatorId, AlertName
| project Alert_TimeGenerated, ActivityGroupNames, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore, AlertName, AlertSeverity, Description, Url, Compromised_Host
| extend timestamp = Alert_TimeGenerated, HostCustomEntity = Compromised_Host, URLCustomEntity = Url

version: 1.2.3
queryFrequency: 1h
requiredDataConnectors:
- connectorId: MicrosoftCloudAppSecurity
  dataTypes:
  - SecurityAlert
- connectorId: AzureSecurityCenter
  dataTypes:
  - SecurityAlert
- connectorId: ThreatIntelligence
  dataTypes:
  - ThreatIntelligenceIndicator
- connectorId: ThreatIntelligenceTaxii
  dataTypes:
  - ThreatIntelligenceIndicator
entityMappings:
- fieldMappings:
  - columnName: HostCustomEntity
    identifier: FullName
  entityType: Host
- fieldMappings:
  - columnName: URLCustomEntity
    identifier: Url
  entityType: URL
kind: Scheduled
queryPeriod: 14d
severity: Medium
query: |
  let dt_lookBack = 1h;
  let ioc_lookBack = 14d;
  ThreatIntelligenceIndicator
  | where TimeGenerated >= ago(ioc_lookBack) and ExpirationDateTime > now()
  | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
  | where Active == true
  // Picking up only IOC's that contain the entities we want
  | where isnotempty(Url)
  // using innerunique to keep perf fast and result set low, we only need one match to indicate potential malicious activity that needs to be investigated
  | join kind=innerunique (
    SecurityAlert
    | where TimeGenerated >= ago(dt_lookBack)
    | extend MSTI = case(AlertName has "TI map" and VendorName == "Microsoft" and ProductName == 'Azure Sentinel', true, false)
    | where MSTI == false
    // Extract URL from JSON data
    | extend Url = extract("(http[s]?://(?:[a-zA-Z]|[0-9]|[$-_@.&+]|[!*\\(\\),]|(?:%[0-9a-fA-F][0-9a-fA-F]))+)", 1,Entities)
    // We only want alerts that actually contain URL data
    | where isnotempty(Url)
    // Extract hostname from JSON data for entity mapping
    | extend Compromised_Host = tostring(parse_json(ExtendedProperties).["Compromised Host"])
    | extend Alert_TimeGenerated = TimeGenerated
  ) on Url
  | where Alert_TimeGenerated < ExpirationDateTime
  | summarize Alert_TimeGenerated = arg_max(Alert_TimeGenerated, *) by IndicatorId, AlertName
  | project Alert_TimeGenerated, ActivityGroupNames, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore, AlertName, AlertSeverity, Description, Url, Compromised_Host
  | extend timestamp = Alert_TimeGenerated, HostCustomEntity = Compromised_Host, URLCustomEntity = Url  
triggerOperator: gt
id: f30a47c1-65fb-42b1-a7f4-00941c12550b
description: |
    'Identifies a match in SecurityAlert data from any URL IOC from TI'
triggerThreshold: 0
name: TI map URL entity to SecurityAlert data
tactics:
- Impact
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/URLEntity_SecurityAlerts.yaml

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/f30a47c1-65fb-42b1-a7f4-00941c12550b')]",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/f30a47c1-65fb-42b1-a7f4-00941c12550b')]",
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules",
      "kind": "Scheduled",
      "apiVersion": "2022-11-01",
      "properties": {
        "displayName": "TI map URL entity to SecurityAlert data",
        "description": "'Identifies a match in SecurityAlert data from any URL IOC from TI'\n",
        "severity": "Medium",
        "enabled": true,
        "query": "let dt_lookBack = 1h;\nlet ioc_lookBack = 14d;\nThreatIntelligenceIndicator\n| where TimeGenerated >= ago(ioc_lookBack) and ExpirationDateTime > now()\n| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId\n| where Active == true\n// Picking up only IOC's that contain the entities we want\n| where isnotempty(Url)\n// using innerunique to keep perf fast and result set low, we only need one match to indicate potential malicious activity that needs to be investigated\n| join kind=innerunique (\n  SecurityAlert\n  | where TimeGenerated >= ago(dt_lookBack)\n  | extend MSTI = case(AlertName has \"TI map\" and VendorName == \"Microsoft\" and ProductName == 'Azure Sentinel', true, false)\n  | where MSTI == false\n  // Extract URL from JSON data\n  | extend Url = extract(\"(http[s]?://(?:[a-zA-Z]|[0-9]|[$-_@.&+]|[!*\\\\(\\\\),]|(?:%[0-9a-fA-F][0-9a-fA-F]))+)\", 1,Entities)\n  // We only want alerts that actually contain URL data\n  | where isnotempty(Url)\n  // Extract hostname from JSON data for entity mapping\n  | extend Compromised_Host = tostring(parse_json(ExtendedProperties).[\"Compromised Host\"])\n  | extend Alert_TimeGenerated = TimeGenerated\n) on Url\n| where Alert_TimeGenerated < ExpirationDateTime\n| summarize Alert_TimeGenerated = arg_max(Alert_TimeGenerated, *) by IndicatorId, AlertName\n| project Alert_TimeGenerated, ActivityGroupNames, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore, AlertName, AlertSeverity, Description, Url, Compromised_Host\n| extend timestamp = Alert_TimeGenerated, HostCustomEntity = Compromised_Host, URLCustomEntity = Url\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "P14D",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0,
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Impact"
        ],
        "alertRuleTemplateName": "f30a47c1-65fb-42b1-a7f4-00941c12550b",
        "customDetails": null,
        "entityMappings": [
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "identifier": "FullName",
                "columnName": "HostCustomEntity"
              }
            ]
          },
          {
            "entityType": "URL",
            "fieldMappings": [
              {
                "identifier": "Url",
                "columnName": "URLCustomEntity"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/URLEntity_SecurityAlerts.yaml",
        "templateVersion": "1.2.3"
      }
    }
  ]
}