TI map Domain entity to CommonSecurityLog

let dt_lookBack = 1h;
let ioc_lookBack = 14d;
let IoCList = externaldata(TimeGenerated:datetime,IoC:string,IoC_Type:string,ExpirationDateTime:datetime,Description:string,Action:string, ConfidenceScore:real, ThreatType:string, Active:string,Type:string, TrafficLightProtocolLevel:string, ActivityGroupNames:string)[@"https://raw.githubusercontent.com/microsoft/mstic/master/RapidReleaseTI/Indicators.csv"] with(format="csv", ignoreFirstRecord=True);
//Create a list of TLDs in our threat feed for later validation of extracted domains
let list_tlds = ThreatIntelligenceIndicator
| where TimeGenerated > ago(ioc_lookBack)
| where isnotempty(DomainName)
| extend DomainName = tolower(DomainName)
| extend parts = split(DomainName, '.')
| extend tld = parts[(array_length(parts)-1)]
| summarize count() by tostring(tld)
| summarize make_list(tld);
let Domain_Indicators = (union isfuzzy=true
(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(DomainName)
| extend TI_DomainEntity = DomainName
),
(IoCList
  | where IoC_Type =~ 'domainname'
  | where ExpirationDateTime > now()
  | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IoC
  | where Active =~ 'True'
  | extend TI_DomainEntity = IoC
  | project-away  IoC_Type
)
);
Domain_Indicators
// 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 (
   CommonSecurityLog
   | 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 domain from RequestURL, if not present extarct it from AdditionalExtentions
   | extend PA_Url = columnifexists("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, '.')
   //Split out the TLD for the purpose of checking if we have any TI indicators with this TLD to match on
   | extend tld = parts[(array_length(parts)-1)]
   //Validate parsed domain by checking TLD against TLDs from threat feed and drop domains where there is no chance of a match
   | 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, IoC
| project CommonSecurityLog_TimeGenerated, Description, ActivityGroupNames, PA_Url, Domain, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore, DeviceAction, DestinationIP, DestinationPort, DeviceName, SourceIP, SourcePort, ApplicationProtocol, RequestMethod, Type, IoC, TI_DomainEntity
| extend timestamp = CommonSecurityLog_TimeGenerated, IPCustomEntity = SourceIP, HostCustomEntity = DeviceName, URLCustomEntity = PA_Url

version: 1.3.0
queryFrequency: 1h
requiredDataConnectors:
- connectorId: ThreatIntelligence
  dataTypes:
  - ThreatIntelligenceIndicator
- connectorId: ThreatIntelligenceTaxii
  dataTypes:
  - ThreatIntelligenceIndicator
entityMappings:
- fieldMappings:
  - columnName: HostCustomEntity
    identifier: FullName
  entityType: Host
- fieldMappings:
  - columnName: IPCustomEntity
    identifier: Address
  entityType: IP
- fieldMappings:
  - columnName: URLCustomEntity
    identifier: Url
  entityType: URL
kind: Scheduled
queryPeriod: 14d
severity: Medium
query: |
  let dt_lookBack = 1h;
  let ioc_lookBack = 14d;
  let IoCList = externaldata(TimeGenerated:datetime,IoC:string,IoC_Type:string,ExpirationDateTime:datetime,Description:string,Action:string, ConfidenceScore:real, ThreatType:string, Active:string,Type:string, TrafficLightProtocolLevel:string, ActivityGroupNames:string)[@"https://raw.githubusercontent.com/microsoft/mstic/master/RapidReleaseTI/Indicators.csv"] with(format="csv", ignoreFirstRecord=True);
  //Create a list of TLDs in our threat feed for later validation of extracted domains
  let list_tlds = ThreatIntelligenceIndicator
  | where TimeGenerated > ago(ioc_lookBack)
  | where isnotempty(DomainName)
  | extend DomainName = tolower(DomainName)
  | extend parts = split(DomainName, '.')
  | extend tld = parts[(array_length(parts)-1)]
  | summarize count() by tostring(tld)
  | summarize make_list(tld);
  let Domain_Indicators = (union isfuzzy=true
  (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(DomainName)
  | extend TI_DomainEntity = DomainName
  ),
  (IoCList
    | where IoC_Type =~ 'domainname'
    | where ExpirationDateTime > now()
    | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IoC
    | where Active =~ 'True'
    | extend TI_DomainEntity = IoC
    | project-away  IoC_Type
  )
  );
  Domain_Indicators
  // 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 (
     CommonSecurityLog
     | 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 domain from RequestURL, if not present extarct it from AdditionalExtentions
     | extend PA_Url = columnifexists("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, '.')
     //Split out the TLD for the purpose of checking if we have any TI indicators with this TLD to match on
     | extend tld = parts[(array_length(parts)-1)]
     //Validate parsed domain by checking TLD against TLDs from threat feed and drop domains where there is no chance of a match
     | 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, IoC
  | project CommonSecurityLog_TimeGenerated, Description, ActivityGroupNames, PA_Url, Domain, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore, DeviceAction, DestinationIP, DestinationPort, DeviceName, SourceIP, SourcePort, ApplicationProtocol, RequestMethod, Type, IoC, TI_DomainEntity
  | extend timestamp = CommonSecurityLog_TimeGenerated, IPCustomEntity = SourceIP, HostCustomEntity = DeviceName, URLCustomEntity = PA_Url  
triggerOperator: gt
id: dd0a6029-ecef-4507-89c4-fc355ac52111
description: |
    'Identifies a match in CommonSecurityLog table from any Domain IOC from TI'
triggerThreshold: 0
name: TI map Domain entity to CommonSecurityLog
tactics:
- Impact
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/DomainEntity_CommonSecurityLog.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/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",
      "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;\nlet ioc_lookBack = 14d;\nlet IoCList = externaldata(TimeGenerated:datetime,IoC:string,IoC_Type:string,ExpirationDateTime:datetime,Description:string,Action:string, ConfidenceScore:real, ThreatType:string, Active:string,Type:string, TrafficLightProtocolLevel:string, ActivityGroupNames:string)[@\"https://raw.githubusercontent.com/microsoft/mstic/master/RapidReleaseTI/Indicators.csv\"] with(format=\"csv\", ignoreFirstRecord=True);\n//Create a list of TLDs in our threat feed for later validation of extracted domains\nlet list_tlds = ThreatIntelligenceIndicator\n| where TimeGenerated > ago(ioc_lookBack)\n| where isnotempty(DomainName)\n| extend DomainName = tolower(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 = (union isfuzzy=true\n(ThreatIntelligenceIndicator\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(DomainName)\n| extend TI_DomainEntity = DomainName\n),\n(IoCList\n  | where IoC_Type =~ 'domainname'\n  | where ExpirationDateTime > now()\n  | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IoC\n  | where Active =~ 'True'\n  | extend TI_DomainEntity = IoC\n  | project-away  IoC_Type\n)\n);\nDomain_Indicators\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   CommonSecurityLog\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 domain from RequestURL, if not present extarct it from AdditionalExtentions\n   | extend PA_Url = columnifexists(\"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   //Split out the TLD for the purpose of checking if we have any TI indicators with this TLD to match on\n   | extend tld = parts[(array_length(parts)-1)]\n   //Validate parsed domain by checking TLD against TLDs from threat feed and drop domains where there is no chance of a match\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, IoC\n| project CommonSecurityLog_TimeGenerated, Description, ActivityGroupNames, PA_Url, Domain, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore, DeviceAction, DestinationIP, DestinationPort, DeviceName, SourceIP, SourcePort, ApplicationProtocol, RequestMethod, Type, IoC, TI_DomainEntity\n| extend timestamp = CommonSecurityLog_TimeGenerated, IPCustomEntity = SourceIP, HostCustomEntity = DeviceName, URLCustomEntity = PA_Url\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "P14D",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0,
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Impact"
        ],
        "alertRuleTemplateName": "dd0a6029-ecef-4507-89c4-fc355ac52111",
        "customDetails": null,
        "entityMappings": [
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "identifier": "FullName",
                "columnName": "HostCustomEntity"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "identifier": "Address",
                "columnName": "IPCustomEntity"
              }
            ]
          },
          {
            "entityType": "URL",
            "fieldMappings": [
              {
                "identifier": "Url",
                "columnName": "URLCustomEntity"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/DomainEntity_CommonSecurityLog.yaml",
        "templateVersion": "1.3.0"
      }
    }
  ]
}