TI map IP entity to CommonSecurityLog

let IPRegex = '[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}';
let dt_lookBack = 1h;
let ioc_lookBack = 14d;
let IoCList = materialize(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));
let IP_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(NetworkIP) or isnotempty(EmailSourceIpAddress) or isnotempty(NetworkDestinationIP) or isnotempty(NetworkSourceIP)
// As there is potentially more than 1 indicator type for matching IP, taking NetworkIP first, then others if that is empty.
// Taking the first non-empty value based on potential IOC match availability
| extend TI_ipEntity = iff(isnotempty(NetworkIP), NetworkIP, NetworkDestinationIP)
| extend TI_ipEntity = iff(isempty(TI_ipEntity) and isnotempty(NetworkSourceIP), NetworkSourceIP, TI_ipEntity)
| extend TI_ipEntity = iff(isempty(TI_ipEntity) and isnotempty(EmailSourceIpAddress), EmailSourceIpAddress, TI_ipEntity)
//Exclude local addresses, using the ipv4_is_private operator
| where ipv4_is_private(TI_ipEntity) == false and  TI_ipEntity !startswith "fe80" and TI_ipEntity !startswith "::" and TI_ipEntity !startswith "127."
),
(IoCList
| where IoC_Type =~ 'IP'
| where ExpirationDateTime > now()
| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IoC
| where Active =~ 'True'
| extend TI_ipEntity = IoC
| project-away  IoC_Type
)
);
IP_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
    | where TimeGenerated >= ago(dt_lookBack)
    | extend MessageIP = extract(IPRegex, 0, Message)
    | extend CS_ipEntity = iff(isnotempty(SourceIP), SourceIP, DestinationIP)
    | extend CS_ipEntity = iff(isempty(CS_ipEntity) and isnotempty(MessageIP), MessageIP, CS_ipEntity)
    | extend CommonSecurityLog_TimeGenerated = TimeGenerated
)
on $left.TI_ipEntity == $right.CS_ipEntity
| where CommonSecurityLog_TimeGenerated < ExpirationDateTime
| summarize CommonSecurityLog_TimeGenerated = arg_max(CommonSecurityLog_TimeGenerated, *) by IndicatorId, CS_ipEntity,  IoC
| project CommonSecurityLog_TimeGenerated, SourceIP, DestinationIP, MessageIP, Message, DeviceVendor, DeviceProduct, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore, TI_ipEntity, CS_ipEntity, LogSeverity, DeviceAction, Type
| extend timestamp = CommonSecurityLog_TimeGenerated, IPCustomEntity = CS_ipEntity

version: 1.1.0
queryFrequency: 1h
requiredDataConnectors:
- connectorId: ThreatIntelligence
  dataTypes:
  - ThreatIntelligenceIndicator
- connectorId: ThreatIntelligenceTaxii
  dataTypes:
  - ThreatIntelligenceIndicator
entityMappings:
- fieldMappings:
  - columnName: IPCustomEntity
    identifier: Address
  entityType: IP
kind: Scheduled
queryPeriod: 14d
severity: Medium
query: |
  let IPRegex = '[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}';
  let dt_lookBack = 1h;
  let ioc_lookBack = 14d;
  let IoCList = materialize(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));
  let IP_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(NetworkIP) or isnotempty(EmailSourceIpAddress) or isnotempty(NetworkDestinationIP) or isnotempty(NetworkSourceIP)
  // As there is potentially more than 1 indicator type for matching IP, taking NetworkIP first, then others if that is empty.
  // Taking the first non-empty value based on potential IOC match availability
  | extend TI_ipEntity = iff(isnotempty(NetworkIP), NetworkIP, NetworkDestinationIP)
  | extend TI_ipEntity = iff(isempty(TI_ipEntity) and isnotempty(NetworkSourceIP), NetworkSourceIP, TI_ipEntity)
  | extend TI_ipEntity = iff(isempty(TI_ipEntity) and isnotempty(EmailSourceIpAddress), EmailSourceIpAddress, TI_ipEntity)
  //Exclude local addresses, using the ipv4_is_private operator
  | where ipv4_is_private(TI_ipEntity) == false and  TI_ipEntity !startswith "fe80" and TI_ipEntity !startswith "::" and TI_ipEntity !startswith "127."
  ),
  (IoCList
  | where IoC_Type =~ 'IP'
  | where ExpirationDateTime > now()
  | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IoC
  | where Active =~ 'True'
  | extend TI_ipEntity = IoC
  | project-away  IoC_Type
  )
  );
  IP_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
      | where TimeGenerated >= ago(dt_lookBack)
      | extend MessageIP = extract(IPRegex, 0, Message)
      | extend CS_ipEntity = iff(isnotempty(SourceIP), SourceIP, DestinationIP)
      | extend CS_ipEntity = iff(isempty(CS_ipEntity) and isnotempty(MessageIP), MessageIP, CS_ipEntity)
      | extend CommonSecurityLog_TimeGenerated = TimeGenerated
  )
  on $left.TI_ipEntity == $right.CS_ipEntity
  | where CommonSecurityLog_TimeGenerated < ExpirationDateTime
  | summarize CommonSecurityLog_TimeGenerated = arg_max(CommonSecurityLog_TimeGenerated, *) by IndicatorId, CS_ipEntity,  IoC
  | project CommonSecurityLog_TimeGenerated, SourceIP, DestinationIP, MessageIP, Message, DeviceVendor, DeviceProduct, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore, TI_ipEntity, CS_ipEntity, LogSeverity, DeviceAction, Type
  | extend timestamp = CommonSecurityLog_TimeGenerated, IPCustomEntity = CS_ipEntity  
triggerOperator: gt
id: 66c81ae2-1f89-4433-be00-2fbbd9ba5ebe
description: |
    'Identifies a match in CommonSecurityLog from any IP IOC from TI'
triggerThreshold: 0
name: TI map IP entity to CommonSecurityLog
tactics:
- Impact
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/IPEntity_CustomSecurityLog.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/66c81ae2-1f89-4433-be00-2fbbd9ba5ebe')]",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/66c81ae2-1f89-4433-be00-2fbbd9ba5ebe')]",
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules",
      "kind": "Scheduled",
      "apiVersion": "2022-11-01",
      "properties": {
        "displayName": "TI map IP entity to CommonSecurityLog",
        "description": "'Identifies a match in CommonSecurityLog from any IP IOC from TI'\n",
        "severity": "Medium",
        "enabled": true,
        "query": "let IPRegex = '[0-9]{1,3}\\\\.[0-9]{1,3}\\\\.[0-9]{1,3}\\\\.[0-9]{1,3}';\nlet dt_lookBack = 1h;\nlet ioc_lookBack = 14d;\nlet IoCList = materialize(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));\nlet IP_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(NetworkIP) or isnotempty(EmailSourceIpAddress) or isnotempty(NetworkDestinationIP) or isnotempty(NetworkSourceIP)\n// As there is potentially more than 1 indicator type for matching IP, taking NetworkIP first, then others if that is empty.\n// Taking the first non-empty value based on potential IOC match availability\n| extend TI_ipEntity = iff(isnotempty(NetworkIP), NetworkIP, NetworkDestinationIP)\n| extend TI_ipEntity = iff(isempty(TI_ipEntity) and isnotempty(NetworkSourceIP), NetworkSourceIP, TI_ipEntity)\n| extend TI_ipEntity = iff(isempty(TI_ipEntity) and isnotempty(EmailSourceIpAddress), EmailSourceIpAddress, TI_ipEntity)\n//Exclude local addresses, using the ipv4_is_private operator\n| where ipv4_is_private(TI_ipEntity) == false and  TI_ipEntity !startswith \"fe80\" and TI_ipEntity !startswith \"::\" and TI_ipEntity !startswith \"127.\"\n),\n(IoCList\n| where IoC_Type =~ 'IP'\n| where ExpirationDateTime > now()\n| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IoC\n| where Active =~ 'True'\n| extend TI_ipEntity = IoC\n| project-away  IoC_Type\n)\n);\nIP_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    | where TimeGenerated >= ago(dt_lookBack)\n    | extend MessageIP = extract(IPRegex, 0, Message)\n    | extend CS_ipEntity = iff(isnotempty(SourceIP), SourceIP, DestinationIP)\n    | extend CS_ipEntity = iff(isempty(CS_ipEntity) and isnotempty(MessageIP), MessageIP, CS_ipEntity)\n    | extend CommonSecurityLog_TimeGenerated = TimeGenerated\n)\non $left.TI_ipEntity == $right.CS_ipEntity\n| where CommonSecurityLog_TimeGenerated < ExpirationDateTime\n| summarize CommonSecurityLog_TimeGenerated = arg_max(CommonSecurityLog_TimeGenerated, *) by IndicatorId, CS_ipEntity,  IoC\n| project CommonSecurityLog_TimeGenerated, SourceIP, DestinationIP, MessageIP, Message, DeviceVendor, DeviceProduct, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore, TI_ipEntity, CS_ipEntity, LogSeverity, DeviceAction, Type\n| extend timestamp = CommonSecurityLog_TimeGenerated, IPCustomEntity = CS_ipEntity\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "P14D",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0,
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Impact"
        ],
        "alertRuleTemplateName": "66c81ae2-1f89-4433-be00-2fbbd9ba5ebe",
        "customDetails": null,
        "entityMappings": [
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "identifier": "Address",
                "columnName": "IPCustomEntity"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/IPEntity_CustomSecurityLog.yaml",
        "templateVersion": "1.1.0"
      }
    }
  ]
}