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; // Look back 1 hour for CommonSecurityLog events
let ioc_lookBack = 14d; // Look back 14 days for threat intelligence indicators
// Fetch threat intelligence indicators related to IP addresses
let IP_Indicators = ThreatIntelIndicators
//extract key part of kv pair
     | extend IndicatorType = replace(@"\[|\]|\""", "", tostring(split(ObservableKey, ":", 0)))
     | where isnotempty(IndicatorType) and IndicatorType == "ipv4-addr"
     | extend NetworkSourceIP = toupper(ObservableValue)
     | extend TrafficLightProtocolLevel = tostring(parse_json(AdditionalFields).TLPLevel)
  | where isnotempty(NetworkSourceIP) 
  | where TimeGenerated >= ago(ioc_lookBack)
  | extend TI_ipEntity = iff(isnotempty(NetworkSourceIP), NetworkSourceIP, NetworkSourceIP)
  | 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)
  | where ipv4_is_private(TI_ipEntity) == false and  TI_ipEntity !startswith "fe80" and TI_ipEntity !startswith "::" and TI_ipEntity !startswith "127."
  | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id
  | where IsActive == true and ValidUntil > now();
// Perform a join between IP indicators and CommonSecurityLog events
IP_Indicators
   | project-reorder *, Tags, TrafficLightProtocolLevel, NetworkSourceIP, Type, TI_ipEntity
  // Use innerunique to keep performance fast and result set low, as we only need one match to indicate potential malicious activity that needs investigation
  | 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
  // Filter out logs that occurred after the expiration of the corresponding indicator
  | where CommonSecurityLog_TimeGenerated < ValidUntil
  // Group the results by IndicatorId and CS_ipEntity, and keep the log entry with the latest timestamp
  | summarize CommonSecurityLog_TimeGenerated = arg_max(CommonSecurityLog_TimeGenerated, *) by Id, CS_ipEntity
  // Select the desired output fields
  | project timestamp = CommonSecurityLog_TimeGenerated, SourceIP, DestinationIP, MessageIP, Message, DeviceVendor, DeviceProduct, Id, ValidUntil, Confidence, TI_ipEntity, CS_ipEntity, LogSeverity, DeviceAction, Type

OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence (NEW)/Analytic Rules/IPEntity_CustomSecurityLog.yaml
query: |
  let IPRegex = '[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}';
  let dt_lookBack = 1h; // Look back 1 hour for CommonSecurityLog events
  let ioc_lookBack = 14d; // Look back 14 days for threat intelligence indicators
  // Fetch threat intelligence indicators related to IP addresses
  let IP_Indicators = ThreatIntelIndicators
  //extract key part of kv pair
       | extend IndicatorType = replace(@"\[|\]|\""", "", tostring(split(ObservableKey, ":", 0)))
       | where isnotempty(IndicatorType) and IndicatorType == "ipv4-addr"
       | extend NetworkSourceIP = toupper(ObservableValue)
       | extend TrafficLightProtocolLevel = tostring(parse_json(AdditionalFields).TLPLevel)
    | where isnotempty(NetworkSourceIP) 
    | where TimeGenerated >= ago(ioc_lookBack)
    | extend TI_ipEntity = iff(isnotempty(NetworkSourceIP), NetworkSourceIP, NetworkSourceIP)
    | 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)
    | where ipv4_is_private(TI_ipEntity) == false and  TI_ipEntity !startswith "fe80" and TI_ipEntity !startswith "::" and TI_ipEntity !startswith "127."
    | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id
    | where IsActive == true and ValidUntil > now();
  // Perform a join between IP indicators and CommonSecurityLog events
  IP_Indicators
     | project-reorder *, Tags, TrafficLightProtocolLevel, NetworkSourceIP, Type, TI_ipEntity
    // Use innerunique to keep performance fast and result set low, as we only need one match to indicate potential malicious activity that needs investigation
    | 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
    // Filter out logs that occurred after the expiration of the corresponding indicator
    | where CommonSecurityLog_TimeGenerated < ValidUntil
    // Group the results by IndicatorId and CS_ipEntity, and keep the log entry with the latest timestamp
    | summarize CommonSecurityLog_TimeGenerated = arg_max(CommonSecurityLog_TimeGenerated, *) by Id, CS_ipEntity
    // Select the desired output fields
    | project timestamp = CommonSecurityLog_TimeGenerated, SourceIP, DestinationIP, MessageIP, Message, DeviceVendor, DeviceProduct, Id, ValidUntil, Confidence, TI_ipEntity, CS_ipEntity, LogSeverity, DeviceAction, Type  
description: |
    This query maps any IP indicators of compromise (IOCs) from threat intelligence (TI), by searching for matches in CommonSecurityLog.
severity: Medium
requiredDataConnectors:
- dataTypes:
  - ThreatIntelligenceIndicator
  connectorId: ThreatIntelligence
- dataTypes:
  - ThreatIntelligenceIndicator
  connectorId: ThreatIntelligenceTaxii
- dataTypes:
  - CommonSecurityLog
  connectorId: CEF
- dataTypes:
  - ThreatIntelligenceIndicator
  connectorId: MicrosoftDefenderThreatIntelligence
name: TI Map IP Entity to CommonSecurityLog
triggerThreshold: 0
tactics:
- CommandAndControl
version: 1.2.3
relevantTechniques:
- T1071
triggerOperator: gt
entityMappings:
- entityType: IP
  fieldMappings:
  - columnName: CS_ipEntity
    identifier: Address
- entityType: IP
  fieldMappings:
  - columnName: SourceIP
    identifier: Address
id: cdd1933b-ef94-48a4-b94a-18d45b902751
kind: Scheduled
queryFrequency: 1h
queryPeriod: 14d

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2024-01-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/cdd1933b-ef94-48a4-b94a-18d45b902751')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/cdd1933b-ef94-48a4-b94a-18d45b902751')]",
      "properties": {
        "alertRuleTemplateName": "cdd1933b-ef94-48a4-b94a-18d45b902751",
        "customDetails": null,
        "description": "This query maps any IP indicators of compromise (IOCs) from threat intelligence (TI), by searching for matches in CommonSecurityLog.\n",
        "displayName": "TI Map IP Entity to CommonSecurityLog",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "CS_ipEntity",
                "identifier": "Address"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "SourceIP",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence (NEW)/Analytic Rules/IPEntity_CustomSecurityLog.yaml",
        "query": "let IPRegex = '[0-9]{1,3}\\\\.[0-9]{1,3}\\\\.[0-9]{1,3}\\\\.[0-9]{1,3}';\nlet dt_lookBack = 1h; // Look back 1 hour for CommonSecurityLog events\nlet ioc_lookBack = 14d; // Look back 14 days for threat intelligence indicators\n// Fetch threat intelligence indicators related to IP addresses\nlet IP_Indicators = ThreatIntelIndicators\n//extract key part of kv pair\n     | extend IndicatorType = replace(@\"\\[|\\]|\\\"\"\", \"\", tostring(split(ObservableKey, \":\", 0)))\n     | where isnotempty(IndicatorType) and IndicatorType == \"ipv4-addr\"\n     | extend NetworkSourceIP = toupper(ObservableValue)\n     | extend TrafficLightProtocolLevel = tostring(parse_json(AdditionalFields).TLPLevel)\n  | where isnotempty(NetworkSourceIP) \n  | where TimeGenerated >= ago(ioc_lookBack)\n  | extend TI_ipEntity = iff(isnotempty(NetworkSourceIP), NetworkSourceIP, NetworkSourceIP)\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  | where ipv4_is_private(TI_ipEntity) == false and  TI_ipEntity !startswith \"fe80\" and TI_ipEntity !startswith \"::\" and TI_ipEntity !startswith \"127.\"\n  | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id\n  | where IsActive == true and ValidUntil > now();\n// Perform a join between IP indicators and CommonSecurityLog events\nIP_Indicators\n   | project-reorder *, Tags, TrafficLightProtocolLevel, NetworkSourceIP, Type, TI_ipEntity\n  // Use innerunique to keep performance fast and result set low, as we only need one match to indicate potential malicious activity that needs investigation\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  )\n  on $left.TI_ipEntity == $right.CS_ipEntity\n  // Filter out logs that occurred after the expiration of the corresponding indicator\n  | where CommonSecurityLog_TimeGenerated < ValidUntil\n  // Group the results by IndicatorId and CS_ipEntity, and keep the log entry with the latest timestamp\n  | summarize CommonSecurityLog_TimeGenerated = arg_max(CommonSecurityLog_TimeGenerated, *) by Id, CS_ipEntity\n  // Select the desired output fields\n  | project timestamp = CommonSecurityLog_TimeGenerated, SourceIP, DestinationIP, MessageIP, Message, DeviceVendor, DeviceProduct, Id, ValidUntil, Confidence, TI_ipEntity, CS_ipEntity, LogSeverity, DeviceAction, Type\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "P14D",
        "severity": "Medium",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "CommandAndControl"
        ],
        "techniques": [
          "T1071"
        ],
        "templateVersion": "1.2.3",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}