TI map Domain entity to CommonSecurityLog

let dt_lookBack = 1h; // Look back 1 hour
let ioc_lookBack = 14d; // Look back 14 days
// Create a list of top-level domains (TLDs) from the threat feed data for later validation
let list_tlds =
    ThreatIntelligenceIndicator
    // Filter indicators based on the specified time range and active indicators
    | where TimeGenerated >= ago(ioc_lookBack)
    | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
    | where Active == true and ExpirationDateTime > now()
    | where isnotempty(DomainName)
    // Convert domain names to lowercase for consistency
    | extend DomainName = tolower(DomainName)
    // Split domain names into parts and extract the TLD
    | extend parts = split(DomainName, '.')
    | extend tld = parts[(array_length(parts) - 1)]
    // Count the occurrences of each TLD
    | summarize count() by tostring(tld)
    // Create a list of TLDs
    | summarize make_list(tld);
// Retrieve threat intelligence indicators within the specified time range
let Domain_Indicators =
    ThreatIntelligenceIndicator
    | where TimeGenerated >= ago(ioc_lookBack)
    | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
    | where Active == true and ExpirationDateTime > now()
    // Filter indicators that have a non-empty domain name
    | where isnotempty(DomainName)
    | extend TI_DomainEntity = DomainName;
// Join threat intelligence indicators with common security logs
Domain_Indicators
| join kind=innerunique (
    CommonSecurityLog
    // Filter common security logs based on the specified time range
    | extend IngestionTime = ingestion_time()
    | where IngestionTime > ago(dt_lookBack)
    | where DeviceEventClassID =~ 'url'
    // Uncomment the line below to only alert on allowed connections
    //| where DeviceAction !~ "block-url"
    // Extract the domain from RequestURL, if not present, extract it from AdditionalExtensions
    | extend PA_Url = column_ifexists("RequestURL", "None")
    | extend PA_Url = iif(isempty(PA_Url) and AdditionalExtensions !startswith "PanOS", extract("([^\\\"]+)", 1, tolower(AdditionalExtensions)), trim('"', PA_Url))
    | extend PA_Url = iif(PA_Url !startswith "http://" and ApplicationProtocol !~ "ssl", strcat('http://', PA_Url), iif(PA_Url !startswith "https://" and ApplicationProtocol =~ "ssl", strcat('https://', PA_Url), PA_Url))
    | extend Domain = trim('"', tostring(parse_url(PA_Url).Host))
    | where isnotempty(Domain)
    | extend Domain = tolower(Domain)
    | extend parts = split(Domain, '.')
    | extend tld = parts[(array_length(parts) - 1)]
    // Validate parsed domain by checking if the TLD is in the threat feed's TLD list
    | where tld in~ (list_tlds)
    | extend CommonSecurityLog_TimeGenerated = TimeGenerated
) on $left.TI_DomainEntity == $right.Domain
| where CommonSecurityLog_TimeGenerated < ExpirationDateTime
| summarize CommonSecurityLog_TimeGenerated = arg_max(CommonSecurityLog_TimeGenerated, *) by IndicatorId
| project CommonSecurityLog_TimeGenerated, Description, ActivityGroupNames, PA_Url, Domain, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore, DeviceAction, DestinationIP, DestinationPort, DeviceName, SourceIP, SourcePort, ApplicationProtocol, RequestMethod, Type, TI_DomainEntity
| extend timestamp = CommonSecurityLog_TimeGenerated

kind: Scheduled
triggerOperator: gt
queryFrequency: 1h
name: TI map Domain entity to CommonSecurityLog
queryPeriod: 14d
id: dd0a6029-ecef-4507-89c4-fc355ac52111
description: |
    Identifies a match in CommonSecurityLog table from any Domain IOC from TI
severity: Medium
query: |
  let dt_lookBack = 1h; // Look back 1 hour
  let ioc_lookBack = 14d; // Look back 14 days
  // Create a list of top-level domains (TLDs) from the threat feed data for later validation
  let list_tlds =
      ThreatIntelligenceIndicator
      // Filter indicators based on the specified time range and active indicators
      | where TimeGenerated >= ago(ioc_lookBack)
      | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
      | where Active == true and ExpirationDateTime > now()
      | where isnotempty(DomainName)
      // Convert domain names to lowercase for consistency
      | extend DomainName = tolower(DomainName)
      // Split domain names into parts and extract the TLD
      | extend parts = split(DomainName, '.')
      | extend tld = parts[(array_length(parts) - 1)]
      // Count the occurrences of each TLD
      | summarize count() by tostring(tld)
      // Create a list of TLDs
      | summarize make_list(tld);
  // Retrieve threat intelligence indicators within the specified time range
  let Domain_Indicators =
      ThreatIntelligenceIndicator
      | where TimeGenerated >= ago(ioc_lookBack)
      | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
      | where Active == true and ExpirationDateTime > now()
      // Filter indicators that have a non-empty domain name
      | where isnotempty(DomainName)
      | extend TI_DomainEntity = DomainName;
  // Join threat intelligence indicators with common security logs
  Domain_Indicators
  | join kind=innerunique (
      CommonSecurityLog
      // Filter common security logs based on the specified time range
      | extend IngestionTime = ingestion_time()
      | where IngestionTime > ago(dt_lookBack)
      | where DeviceEventClassID =~ 'url'
      // Uncomment the line below to only alert on allowed connections
      //| where DeviceAction !~ "block-url"
      // Extract the domain from RequestURL, if not present, extract it from AdditionalExtensions
      | extend PA_Url = column_ifexists("RequestURL", "None")
      | extend PA_Url = iif(isempty(PA_Url) and AdditionalExtensions !startswith "PanOS", extract("([^\\\"]+)", 1, tolower(AdditionalExtensions)), trim('"', PA_Url))
      | extend PA_Url = iif(PA_Url !startswith "http://" and ApplicationProtocol !~ "ssl", strcat('http://', PA_Url), iif(PA_Url !startswith "https://" and ApplicationProtocol =~ "ssl", strcat('https://', PA_Url), PA_Url))
      | extend Domain = trim('"', tostring(parse_url(PA_Url).Host))
      | where isnotempty(Domain)
      | extend Domain = tolower(Domain)
      | extend parts = split(Domain, '.')
      | extend tld = parts[(array_length(parts) - 1)]
      // Validate parsed domain by checking if the TLD is in the threat feed's TLD list
      | where tld in~ (list_tlds)
      | extend CommonSecurityLog_TimeGenerated = TimeGenerated
  ) on $left.TI_DomainEntity == $right.Domain
  | where CommonSecurityLog_TimeGenerated < ExpirationDateTime
  | summarize CommonSecurityLog_TimeGenerated = arg_max(CommonSecurityLog_TimeGenerated, *) by IndicatorId
  | project CommonSecurityLog_TimeGenerated, Description, ActivityGroupNames, PA_Url, Domain, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore, DeviceAction, DestinationIP, DestinationPort, DeviceName, SourceIP, SourcePort, ApplicationProtocol, RequestMethod, Type, TI_DomainEntity
  | extend timestamp = CommonSecurityLog_TimeGenerated  
version: 1.4.0
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/DomainEntity_CommonSecurityLog.yaml
entityMappings:
- entityType: Host
  fieldMappings:
  - identifier: HostName
    columnName: DeviceName
- entityType: IP
  fieldMappings:
  - identifier: Address
    columnName: SourceIP
- entityType: URL
  fieldMappings:
  - identifier: Url
    columnName: PA_Url
requiredDataConnectors:
- connectorId: ThreatIntelligence
  dataTypes:
  - ThreatIntelligenceIndicator
- connectorId: ThreatIntelligenceTaxii
  dataTypes:
  - ThreatIntelligenceIndicator
- connectorId: MicrosoftDefenderThreatIntelligence
  dataTypes:
  - ThreatIntelligenceIndicator
tactics:
- Impact
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/dd0a6029-ecef-4507-89c4-fc355ac52111')]",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/dd0a6029-ecef-4507-89c4-fc355ac52111')]",
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules",
      "kind": "Scheduled",
      "apiVersion": "2022-11-01-preview",
      "properties": {
        "displayName": "TI map Domain entity to CommonSecurityLog",
        "description": "Identifies a match in CommonSecurityLog table from any Domain IOC from TI\n",
        "severity": "Medium",
        "enabled": true,
        "query": "let dt_lookBack = 1h; // Look back 1 hour\nlet ioc_lookBack = 14d; // Look back 14 days\n// Create a list of top-level domains (TLDs) from the threat feed data for later validation\nlet list_tlds =\n    ThreatIntelligenceIndicator\n    // Filter indicators based on the specified time range and active indicators\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    // Convert domain names to lowercase for consistency\n    | extend DomainName = tolower(DomainName)\n    // Split domain names into parts and extract the TLD\n    | extend parts = split(DomainName, '.')\n    | extend tld = parts[(array_length(parts) - 1)]\n    // Count the occurrences of each TLD\n    | summarize count() by tostring(tld)\n    // Create a list of TLDs\n    | summarize make_list(tld);\n// Retrieve threat intelligence indicators within the specified time range\nlet Domain_Indicators =\n    ThreatIntelligenceIndicator\n    | where TimeGenerated >= ago(ioc_lookBack)\n    | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId\n    | where Active == true and ExpirationDateTime > now()\n    // Filter indicators that have a non-empty domain name\n    | where isnotempty(DomainName)\n    | extend TI_DomainEntity = DomainName;\n// Join threat intelligence indicators with common security logs\nDomain_Indicators\n| join kind=innerunique (\n    CommonSecurityLog\n    // Filter common security logs based on the specified time range\n    | extend IngestionTime = ingestion_time()\n    | where IngestionTime > ago(dt_lookBack)\n    | where DeviceEventClassID =~ 'url'\n    // Uncomment the line below to only alert on allowed connections\n    //| where DeviceAction !~ \"block-url\"\n    // Extract the domain from RequestURL, if not present, extract it from AdditionalExtensions\n    | extend PA_Url = column_ifexists(\"RequestURL\", \"None\")\n    | extend PA_Url = iif(isempty(PA_Url) and AdditionalExtensions !startswith \"PanOS\", extract(\"([^\\\\\\\"]+)\", 1, tolower(AdditionalExtensions)), trim('\"', PA_Url))\n    | extend PA_Url = iif(PA_Url !startswith \"http://\" and ApplicationProtocol !~ \"ssl\", strcat('http://', PA_Url), iif(PA_Url !startswith \"https://\" and ApplicationProtocol =~ \"ssl\", strcat('https://', PA_Url), PA_Url))\n    | extend Domain = trim('\"', tostring(parse_url(PA_Url).Host))\n    | where isnotempty(Domain)\n    | extend Domain = tolower(Domain)\n    | extend parts = split(Domain, '.')\n    | extend tld = parts[(array_length(parts) - 1)]\n    // Validate parsed domain by checking if the TLD is in the threat feed's TLD list\n    | where tld in~ (list_tlds)\n    | extend CommonSecurityLog_TimeGenerated = TimeGenerated\n) on $left.TI_DomainEntity == $right.Domain\n| where CommonSecurityLog_TimeGenerated < ExpirationDateTime\n| summarize CommonSecurityLog_TimeGenerated = arg_max(CommonSecurityLog_TimeGenerated, *) by IndicatorId\n| project CommonSecurityLog_TimeGenerated, Description, ActivityGroupNames, PA_Url, Domain, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore, DeviceAction, DestinationIP, DestinationPort, DeviceName, SourceIP, SourcePort, ApplicationProtocol, RequestMethod, Type, TI_DomainEntity\n| extend timestamp = CommonSecurityLog_TimeGenerated\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "P14D",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0,
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Impact"
        ],
        "alertRuleTemplateName": "dd0a6029-ecef-4507-89c4-fc355ac52111",
        "customDetails": null,
        "entityMappings": [
          {
            "fieldMappings": [
              {
                "identifier": "HostName",
                "columnName": "DeviceName"
              }
            ],
            "entityType": "Host"
          },
          {
            "fieldMappings": [
              {
                "identifier": "Address",
                "columnName": "SourceIP"
              }
            ],
            "entityType": "IP"
          },
          {
            "fieldMappings": [
              {
                "identifier": "Url",
                "columnName": "PA_Url"
              }
            ],
            "entityType": "URL"
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/DomainEntity_CommonSecurityLog.yaml",
        "templateVersion": "1.4.0"
      }
    }
  ]
}