TI map IP entity to AzureNetworkAnalytics_CL (NSG Flow Logs)

let dt_lookBack = 1h; // Look back 1 hour for AzureNetworkAnalytics_CL logs
let ioc_lookBack = 14d; // Look back 14 days for threat intelligence indicators
// Fetch threat intelligence indicators related to IP addresses
let IP_Indicators = ThreatIntelligenceIndicator
  | where TimeGenerated >= ago(ioc_lookBack)
  | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
  | where Active == true and ExpirationDateTime > now()
  | where isnotempty(NetworkIP) or isnotempty(EmailSourceIpAddress) or isnotempty(NetworkDestinationIP) or isnotempty(NetworkSourceIP)
  | 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)
  | where ipv4_is_private(TI_ipEntity) == false and  TI_ipEntity !startswith "fe80" and TI_ipEntity !startswith "::" and TI_ipEntity !startswith "127.";
// Perform a join between IP indicators and AzureNetworkAnalytics_CL logs for NSG Flow information
IP_Indicators
  // 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 (
      AzureNetworkAnalytics_CL
      | where TimeGenerated >= ago(dt_lookBack)
      | extend AzureNetworkAnalytics_CL_TimeGenerated = TimeGenerated
      | extend PIPs = split(PublicIPs_s, '|', 0)
      | extend PIP = tostring(PIPs[0])
  )
  on $left.TI_ipEntity == $right.PIP
  // Filter out logs that occurred after the expiration of the corresponding indicator
  | where AzureNetworkAnalytics_CL_TimeGenerated < ExpirationDateTime
  // Filter out NSG Flow logs that are not allowed (FlowStatus_s == "A")
  | where FlowStatus_s == "A"
  // Group the results by IndicatorId and PIP (Public IP), and keep the log entry with the latest timestamp
  | summarize AzureNetworkAnalytics_CL_TimeGenerated = arg_max(AzureNetworkAnalytics_CL_TimeGenerated, *) by IndicatorId, PIP
  // Select the desired output fields
  | project AzureNetworkAnalytics_CL_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, Url, ExpirationDateTime, ConfidenceScore,
    TI_ipEntity, Computer, FlowDirection_s, FlowStatus_s, FlowType_s, SrcPublicIPs_s, DestPublicIPs_s, PublicIPs_s, L7Protocol_s, DestPort_d, NetworkIP, NetworkDestinationIP, NetworkSourceIP, EmailSourceIpAddress, Type
  // Extract hostname and DNS domain from the Computer field
  | extend HostName = tostring(split(Computer, '.', 0)[0]), DnsDomain = tostring(strcat_array(array_slice(split(Computer, '.'), 1, -1), '.'))
  // Rename the timestamp field
  | extend timestamp = AzureNetworkAnalytics_CL_TimeGenerated

severity: Medium
requiredDataConnectors:
- dataTypes:
  - ThreatIntelligenceIndicator
  connectorId: ThreatIntelligence
- dataTypes:
  - ThreatIntelligenceIndicator
  connectorId: ThreatIntelligenceTaxii
- dataTypes:
  - ThreatIntelligenceIndicator
  connectorId: MicrosoftDefenderThreatIntelligence
id: a4025a76-6490-4e6b-bb69-d02be4b03f07
tactics:
- Impact
queryFrequency: 1h
triggerOperator: gt
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/IPEntity_AzureNetworkAnalytics.yaml
description: |
    Identifies a match in AzureNetworkAnalytics_CL (NSG Flow Logs) from any IP IOC from TI that was Allowed
triggerThreshold: 0
kind: Scheduled
name: TI map IP entity to AzureNetworkAnalytics_CL (NSG Flow Logs)
query: |
  let dt_lookBack = 1h; // Look back 1 hour for AzureNetworkAnalytics_CL logs
  let ioc_lookBack = 14d; // Look back 14 days for threat intelligence indicators
  // Fetch threat intelligence indicators related to IP addresses
  let IP_Indicators = ThreatIntelligenceIndicator
    | where TimeGenerated >= ago(ioc_lookBack)
    | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
    | where Active == true and ExpirationDateTime > now()
    | where isnotempty(NetworkIP) or isnotempty(EmailSourceIpAddress) or isnotempty(NetworkDestinationIP) or isnotempty(NetworkSourceIP)
    | 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)
    | where ipv4_is_private(TI_ipEntity) == false and  TI_ipEntity !startswith "fe80" and TI_ipEntity !startswith "::" and TI_ipEntity !startswith "127.";
  // Perform a join between IP indicators and AzureNetworkAnalytics_CL logs for NSG Flow information
  IP_Indicators
    // 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 (
        AzureNetworkAnalytics_CL
        | where TimeGenerated >= ago(dt_lookBack)
        | extend AzureNetworkAnalytics_CL_TimeGenerated = TimeGenerated
        | extend PIPs = split(PublicIPs_s, '|', 0)
        | extend PIP = tostring(PIPs[0])
    )
    on $left.TI_ipEntity == $right.PIP
    // Filter out logs that occurred after the expiration of the corresponding indicator
    | where AzureNetworkAnalytics_CL_TimeGenerated < ExpirationDateTime
    // Filter out NSG Flow logs that are not allowed (FlowStatus_s == "A")
    | where FlowStatus_s == "A"
    // Group the results by IndicatorId and PIP (Public IP), and keep the log entry with the latest timestamp
    | summarize AzureNetworkAnalytics_CL_TimeGenerated = arg_max(AzureNetworkAnalytics_CL_TimeGenerated, *) by IndicatorId, PIP
    // Select the desired output fields
    | project AzureNetworkAnalytics_CL_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, Url, ExpirationDateTime, ConfidenceScore,
      TI_ipEntity, Computer, FlowDirection_s, FlowStatus_s, FlowType_s, SrcPublicIPs_s, DestPublicIPs_s, PublicIPs_s, L7Protocol_s, DestPort_d, NetworkIP, NetworkDestinationIP, NetworkSourceIP, EmailSourceIpAddress, Type
    // Extract hostname and DNS domain from the Computer field
    | extend HostName = tostring(split(Computer, '.', 0)[0]), DnsDomain = tostring(strcat_array(array_slice(split(Computer, '.'), 1, -1), '.'))
    // Rename the timestamp field
    | extend timestamp = AzureNetworkAnalytics_CL_TimeGenerated  
entityMappings:
- entityType: Host
  fieldMappings:
  - columnName: HostName
    identifier: HostName
  - columnName: DnsDomain
    identifier: DnsDomain
- entityType: IP
  fieldMappings:
  - columnName: TI_ipEntity
    identifier: Address
- entityType: URL
  fieldMappings:
  - columnName: Url
    identifier: Url
version: 1.4.0
queryPeriod: 14d

{
  "$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/a4025a76-6490-4e6b-bb69-d02be4b03f07')]",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/a4025a76-6490-4e6b-bb69-d02be4b03f07')]",
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules",
      "kind": "Scheduled",
      "apiVersion": "2022-11-01-preview",
      "properties": {
        "displayName": "TI map IP entity to AzureNetworkAnalytics_CL (NSG Flow Logs)",
        "description": "Identifies a match in AzureNetworkAnalytics_CL (NSG Flow Logs) from any IP IOC from TI that was Allowed\n",
        "severity": "Medium",
        "enabled": true,
        "query": "let dt_lookBack = 1h; // Look back 1 hour for AzureNetworkAnalytics_CL logs\nlet ioc_lookBack = 14d; // Look back 14 days for threat intelligence indicators\n// Fetch threat intelligence indicators related to IP addresses\nlet IP_Indicators = 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(NetworkIP) or isnotempty(EmailSourceIpAddress) or isnotempty(NetworkDestinationIP) or isnotempty(NetworkSourceIP)\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  | where ipv4_is_private(TI_ipEntity) == false and  TI_ipEntity !startswith \"fe80\" and TI_ipEntity !startswith \"::\" and TI_ipEntity !startswith \"127.\";\n// Perform a join between IP indicators and AzureNetworkAnalytics_CL logs for NSG Flow information\nIP_Indicators\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      AzureNetworkAnalytics_CL\n      | where TimeGenerated >= ago(dt_lookBack)\n      | extend AzureNetworkAnalytics_CL_TimeGenerated = TimeGenerated\n      | extend PIPs = split(PublicIPs_s, '|', 0)\n      | extend PIP = tostring(PIPs[0])\n  )\n  on $left.TI_ipEntity == $right.PIP\n  // Filter out logs that occurred after the expiration of the corresponding indicator\n  | where AzureNetworkAnalytics_CL_TimeGenerated < ExpirationDateTime\n  // Filter out NSG Flow logs that are not allowed (FlowStatus_s == \"A\")\n  | where FlowStatus_s == \"A\"\n  // Group the results by IndicatorId and PIP (Public IP), and keep the log entry with the latest timestamp\n  | summarize AzureNetworkAnalytics_CL_TimeGenerated = arg_max(AzureNetworkAnalytics_CL_TimeGenerated, *) by IndicatorId, PIP\n  // Select the desired output fields\n  | project AzureNetworkAnalytics_CL_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, Url, ExpirationDateTime, ConfidenceScore,\n    TI_ipEntity, Computer, FlowDirection_s, FlowStatus_s, FlowType_s, SrcPublicIPs_s, DestPublicIPs_s, PublicIPs_s, L7Protocol_s, DestPort_d, NetworkIP, NetworkDestinationIP, NetworkSourceIP, EmailSourceIpAddress, Type\n  // Extract hostname and DNS domain from the Computer field\n  | extend HostName = tostring(split(Computer, '.', 0)[0]), DnsDomain = tostring(strcat_array(array_slice(split(Computer, '.'), 1, -1), '.'))\n  // Rename the timestamp field\n  | extend timestamp = AzureNetworkAnalytics_CL_TimeGenerated\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "P14D",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0,
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Impact"
        ],
        "alertRuleTemplateName": "a4025a76-6490-4e6b-bb69-d02be4b03f07",
        "customDetails": null,
        "entityMappings": [
          {
            "fieldMappings": [
              {
                "identifier": "HostName",
                "columnName": "HostName"
              },
              {
                "identifier": "DnsDomain",
                "columnName": "DnsDomain"
              }
            ],
            "entityType": "Host"
          },
          {
            "fieldMappings": [
              {
                "identifier": "Address",
                "columnName": "TI_ipEntity"
              }
            ],
            "entityType": "IP"
          },
          {
            "fieldMappings": [
              {
                "identifier": "Url",
                "columnName": "Url"
              }
            ],
            "entityType": "URL"
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/IPEntity_AzureNetworkAnalytics.yaml",
        "templateVersion": "1.4.0"
      }
    }
  ]
}