Microsoft Sentinel Analytic Rules
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TI map Domain entity to SecurityAlert

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Id87890d78-3e05-43ec-9ab9-ba32f4e01250
RulenameTI map Domain entity to SecurityAlert
DescriptionIdentifies a match in SecurityAlert table from any Domain IOC from TI
SeverityMedium
TacticsImpact
Required data connectorsAzureSecurityCenter
MicrosoftCloudAppSecurity
MicrosoftDefenderThreatIntelligence
ThreatIntelligence
ThreatIntelligenceTaxii
KindScheduled
Query frequency1h
Query period14d
Trigger threshold0
Trigger operatorgt
Source Urihttps://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/DomainEntity_SecurityAlert.yaml
Version1.4.1
Arm template87890d78-3e05-43ec-9ab9-ba32f4e01250.json
Deploy To Azure
let dt_lookBack = 1h; // Lookback time for recent data, set to 1 hour
let ioc_lookBack = 14d; // Lookback time for threat feed data, set to 14 days
// Create a list of TLDs in our threat feed for later validation
let list_tlds = ThreatIntelligenceIndicator
  | where TimeGenerated >= ago(ioc_lookBack)
  | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
  | where Active == true and ExpirationDateTime > now()
  | where isnotempty(DomainName)
  | extend parts = split(DomainName, '.')
  | extend tld = parts[(array_length(parts)-1)]
  | summarize count() by tostring(tld)
  | summarize make_list(tld);
let Domain_Indicators = ThreatIntelligenceIndicator
  | where TimeGenerated >= ago(ioc_lookBack)
  | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
  | where Active == true and ExpirationDateTime > now()
  // Picking up only IOC's that contain the entities we want
  | where isnotempty(DomainName)
  | extend TI_DomainEntity = DomainName;
Domain_Indicators
  // Using innerunique to keep performance 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 domain patterns from message
    | extend domain = todynamic(dynamic_to_json(extract_all(@"(((xn--)?[a-z0-9\-]+\.)+([a-z]+|(xn--[a-z0-9]+)))", dynamic([1,1]), tolower(Entities))))
    | mv-expand domain
    | extend domain = tostring(domain[0])
    | extend parts = split(domain, '.')
    // Split out the TLD
    | extend tld = parts[(array_length(parts)-1)]
    // Validate parsed domain by checking if the TLD is in the list of TLDs in our threat feed
    | where tld in~ (list_tlds)
    // Converting Entities into dynamic data type and use mv-expand to unpack the array
    | extend EntitiesDynamicArray = parse_json(Entities)
    | mv-apply EntitiesDynamicArray on
      (summarize
        HostName = take_anyif(tostring(EntitiesDynamicArray.HostName), EntitiesDynamicArray.Type == "host"),
        IP_addr = take_anyif(tostring(EntitiesDynamicArray.Address), EntitiesDynamicArray.Type == "ip")
      )
    | extend Alert_TimeGenerated = TimeGenerated
    | extend Alert_Description = Description
  ) on $left.TI_DomainEntity == $right.domain
  | where Alert_TimeGenerated < ExpirationDateTime
  | summarize Alert_TimeGenerated = arg_max(Alert_TimeGenerated, *) by IndicatorId, AlertName
  | project Alert_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore, DomainName, AlertName, Alert_Description, ProviderName, AlertSeverity, ConfidenceLevel, HostName, IP_addr, Url, Entities, Type, TI_DomainEntity
  | extend timestamp = Alert_TimeGenerated
triggerOperator: gt
version: 1.4.1
query: |
  let dt_lookBack = 1h; // Lookback time for recent data, set to 1 hour
  let ioc_lookBack = 14d; // Lookback time for threat feed data, set to 14 days
  // Create a list of TLDs in our threat feed for later validation
  let list_tlds = ThreatIntelligenceIndicator
    | where TimeGenerated >= ago(ioc_lookBack)
    | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
    | where Active == true and ExpirationDateTime > now()
    | where isnotempty(DomainName)
    | extend parts = split(DomainName, '.')
    | extend tld = parts[(array_length(parts)-1)]
    | summarize count() by tostring(tld)
    | summarize make_list(tld);
  let Domain_Indicators = ThreatIntelligenceIndicator
    | where TimeGenerated >= ago(ioc_lookBack)
    | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
    | where Active == true and ExpirationDateTime > now()
    // Picking up only IOC's that contain the entities we want
    | where isnotempty(DomainName)
    | extend TI_DomainEntity = DomainName;
  Domain_Indicators
    // Using innerunique to keep performance 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 domain patterns from message
      | extend domain = todynamic(dynamic_to_json(extract_all(@"(((xn--)?[a-z0-9\-]+\.)+([a-z]+|(xn--[a-z0-9]+)))", dynamic([1,1]), tolower(Entities))))
      | mv-expand domain
      | extend domain = tostring(domain[0])
      | extend parts = split(domain, '.')
      // Split out the TLD
      | extend tld = parts[(array_length(parts)-1)]
      // Validate parsed domain by checking if the TLD is in the list of TLDs in our threat feed
      | where tld in~ (list_tlds)
      // Converting Entities into dynamic data type and use mv-expand to unpack the array
      | extend EntitiesDynamicArray = parse_json(Entities)
      | mv-apply EntitiesDynamicArray on
        (summarize
          HostName = take_anyif(tostring(EntitiesDynamicArray.HostName), EntitiesDynamicArray.Type == "host"),
          IP_addr = take_anyif(tostring(EntitiesDynamicArray.Address), EntitiesDynamicArray.Type == "ip")
        )
      | extend Alert_TimeGenerated = TimeGenerated
      | extend Alert_Description = Description
    ) on $left.TI_DomainEntity == $right.domain
    | where Alert_TimeGenerated < ExpirationDateTime
    | summarize Alert_TimeGenerated = arg_max(Alert_TimeGenerated, *) by IndicatorId, AlertName
    | project Alert_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore, DomainName, AlertName, Alert_Description, ProviderName, AlertSeverity, ConfidenceLevel, HostName, IP_addr, Url, Entities, Type, TI_DomainEntity
    | extend timestamp = Alert_TimeGenerated  
entityMappings:
- entityType: Host
  fieldMappings:
  - columnName: HostName
    identifier: HostName
- entityType: IP
  fieldMappings:
  - columnName: IP_addr
    identifier: Address
- entityType: URL
  fieldMappings:
  - columnName: Url
    identifier: Url
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/DomainEntity_SecurityAlert.yaml
queryFrequency: 1h
requiredDataConnectors:
- connectorId: ThreatIntelligence
  dataTypes:
  - ThreatIntelligenceIndicator
- connectorId: ThreatIntelligenceTaxii
  dataTypes:
  - ThreatIntelligenceIndicator
- connectorId: MicrosoftCloudAppSecurity
  dataTypes:
  - SecurityAlert
- connectorId: AzureSecurityCenter
  dataTypes:
  - SecurityAlert
- connectorId: MicrosoftDefenderThreatIntelligence
  dataTypes:
  - ThreatIntelligenceIndicator
name: TI map Domain entity to SecurityAlert
queryPeriod: 14d
severity: Medium
kind: Scheduled
tactics:
- Impact
id: 87890d78-3e05-43ec-9ab9-ba32f4e01250
description: |
    'Identifies a match in SecurityAlert table from any Domain IOC from TI'
triggerThreshold: 0
{
  "$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/87890d78-3e05-43ec-9ab9-ba32f4e01250')]",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/87890d78-3e05-43ec-9ab9-ba32f4e01250')]",
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules",
      "kind": "Scheduled",
      "apiVersion": "2022-11-01-preview",
      "properties": {
        "displayName": "TI map Domain entity to SecurityAlert",
        "description": "'Identifies a match in SecurityAlert table from any Domain IOC from TI'\n",
        "severity": "Medium",
        "enabled": true,
        "query": "let dt_lookBack = 1h; // Lookback time for recent data, set to 1 hour\nlet ioc_lookBack = 14d; // Lookback time for threat feed data, set to 14 days\n// Create a list of TLDs in our threat feed for later validation\nlet list_tlds = ThreatIntelligenceIndicator\n  | where TimeGenerated >= ago(ioc_lookBack)\n  | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId\n  | where Active == true and ExpirationDateTime > now()\n  | where isnotempty(DomainName)\n  | extend parts = split(DomainName, '.')\n  | extend tld = parts[(array_length(parts)-1)]\n  | summarize count() by tostring(tld)\n  | summarize make_list(tld);\nlet Domain_Indicators = ThreatIntelligenceIndicator\n  | where TimeGenerated >= ago(ioc_lookBack)\n  | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId\n  | where Active == true and ExpirationDateTime > now()\n  // Picking up only IOC's that contain the entities we want\n  | where isnotempty(DomainName)\n  | extend TI_DomainEntity = DomainName;\nDomain_Indicators\n  // Using innerunique to keep performance 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 domain patterns from message\n    | extend domain = todynamic(dynamic_to_json(extract_all(@\"(((xn--)?[a-z0-9\\-]+\\.)+([a-z]+|(xn--[a-z0-9]+)))\", dynamic([1,1]), tolower(Entities))))\n    | mv-expand domain\n    | extend domain = tostring(domain[0])\n    | extend parts = split(domain, '.')\n    // Split out the TLD\n    | extend tld = parts[(array_length(parts)-1)]\n    // Validate parsed domain by checking if the TLD is in the list of TLDs in our threat feed\n    | where tld in~ (list_tlds)\n    // Converting Entities into dynamic data type and use mv-expand to unpack the array\n    | extend EntitiesDynamicArray = parse_json(Entities)\n    | mv-apply EntitiesDynamicArray on\n      (summarize\n        HostName = take_anyif(tostring(EntitiesDynamicArray.HostName), EntitiesDynamicArray.Type == \"host\"),\n        IP_addr = take_anyif(tostring(EntitiesDynamicArray.Address), EntitiesDynamicArray.Type == \"ip\")\n      )\n    | extend Alert_TimeGenerated = TimeGenerated\n    | extend Alert_Description = Description\n  ) on $left.TI_DomainEntity == $right.domain\n  | where Alert_TimeGenerated < ExpirationDateTime\n  | summarize Alert_TimeGenerated = arg_max(Alert_TimeGenerated, *) by IndicatorId, AlertName\n  | project Alert_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore, DomainName, AlertName, Alert_Description, ProviderName, AlertSeverity, ConfidenceLevel, HostName, IP_addr, Url, Entities, Type, TI_DomainEntity\n  | extend timestamp = Alert_TimeGenerated\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "P14D",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0,
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Impact"
        ],
        "alertRuleTemplateName": "87890d78-3e05-43ec-9ab9-ba32f4e01250",
        "customDetails": null,
        "entityMappings": [
          {
            "fieldMappings": [
              {
                "columnName": "HostName",
                "identifier": "HostName"
              }
            ],
            "entityType": "Host"
          },
          {
            "fieldMappings": [
              {
                "columnName": "IP_addr",
                "identifier": "Address"
              }
            ],
            "entityType": "IP"
          },
          {
            "fieldMappings": [
              {
                "columnName": "Url",
                "identifier": "Url"
              }
            ],
            "entityType": "URL"
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/DomainEntity_SecurityAlert.yaml",
        "templateVersion": "1.4.1"
      }
    }
  ]
}