TI Map URL Entity to AuditLogs

let dt_lookBack = 1h;
let ioc_lookBack = 14d;
let AuditEvents = materialize(AuditLogs
  | where TimeGenerated >= ago(dt_lookBack)
  // Extract the URL that is contained within the JSON data
  | extend Url = extract("(http[s]?://(?:[a-zA-Z]|[0-9]|[$-_@.&+]|[!*\\(\\),]|(?:%[0-9a-fA-F][0-9a-fA-F]))+)", 1,tostring(TargetResources))
  | where isnotempty(Url)
  | extend userPrincipalName = tostring(parse_json(tostring(InitiatedBy.user)).userPrincipalName)
  | extend TargetResourceDisplayName = tostring(TargetResources[0].displayName)
  | extend Audit_TimeGenerated = TimeGenerated);
let AuditUrls = AuditEvents | distinct Url = tolower(Url) | summarize make_list(Url);
ThreatIntelligenceIndicator
| where isnotempty(Url)
| where TimeGenerated >= ago(ioc_lookBack)
| where tolower(Url) in (AuditUrls)
| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
| where Active == true and ExpirationDateTime > now()
| where Description !contains_cs "State: inactive;" and Description !contains_cs "State: falsepos;"
// 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 (AuditEvents) on Url
| where Audit_TimeGenerated < ExpirationDateTime
| summarize Audit_TimeGenerated = arg_max(Audit_TimeGenerated, *) by IndicatorId, Url
| project Audit_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore,
OperationName, Identity, userPrincipalName, TargetResourceDisplayName, Url
| extend AccountName = tostring(split(userPrincipalName, "@")[0]), AccountUPNSuffix = tostring(split(userPrincipalName, "@")[1])
| extend HostName = tostring(split(TargetResourceDisplayName, ".")[0]), DomainIndex = toint(indexof(TargetResourceDisplayName, '.'))
| extend HostNameDomain = iff(DomainIndex != -1, substring(TargetResourceDisplayName, DomainIndex + 1), TargetResourceDisplayName)

relevantTechniques:
- T1071
name: TI Map URL Entity to AuditLogs
requiredDataConnectors:
- dataTypes:
  - AuditLogs
  connectorId: AzureActiveDirectory
- dataTypes:
  - ThreatIntelligenceIndicator
  connectorId: ThreatIntelligence
- dataTypes:
  - ThreatIntelligenceIndicator
  connectorId: ThreatIntelligenceTaxii
- dataTypes:
  - ThreatIntelligenceIndicator
  connectorId: MicrosoftDefenderThreatIntelligence
entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: userPrincipalName
  - identifier: Name
    columnName: AccountName
  - identifier: UPNSuffix
    columnName: AccountUPNSuffix
  entityType: Account
- fieldMappings:
  - identifier: FullName
    columnName: TargetResourceDisplayName
  - identifier: HostName
    columnName: HostName
  - identifier: DnsDomain
    columnName: HostNameDomain
  entityType: Host
- fieldMappings:
  - identifier: Url
    columnName: Url
  entityType: URL
triggerThreshold: 0
id: 712fab52-2a7d-401e-a08c-ff939cc7c25e
tactics:
- CommandAndControl
version: 1.2.8
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/URLEntity_AuditLogs.yaml
queryPeriod: 14d
kind: Scheduled
queryFrequency: 1h
severity: Medium
description: |
    'This query identifies any URL indicators of compromise (IOCs) from threat intelligence (TI) by searching for matches in AuditLogs.'
query: |
  let dt_lookBack = 1h;
  let ioc_lookBack = 14d;
  let AuditEvents = materialize(AuditLogs
    | where TimeGenerated >= ago(dt_lookBack)
    // Extract the URL that is contained within the JSON data
    | extend Url = extract("(http[s]?://(?:[a-zA-Z]|[0-9]|[$-_@.&+]|[!*\\(\\),]|(?:%[0-9a-fA-F][0-9a-fA-F]))+)", 1,tostring(TargetResources))
    | where isnotempty(Url)
    | extend userPrincipalName = tostring(parse_json(tostring(InitiatedBy.user)).userPrincipalName)
    | extend TargetResourceDisplayName = tostring(TargetResources[0].displayName)
    | extend Audit_TimeGenerated = TimeGenerated);
  let AuditUrls = AuditEvents | distinct Url = tolower(Url) | summarize make_list(Url);
  ThreatIntelligenceIndicator
  | where isnotempty(Url)
  | where TimeGenerated >= ago(ioc_lookBack)
  | where tolower(Url) in (AuditUrls)
  | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
  | where Active == true and ExpirationDateTime > now()
  | where Description !contains_cs "State: inactive;" and Description !contains_cs "State: falsepos;"
  // 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 (AuditEvents) on Url
  | where Audit_TimeGenerated < ExpirationDateTime
  | summarize Audit_TimeGenerated = arg_max(Audit_TimeGenerated, *) by IndicatorId, Url
  | project Audit_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore,
  OperationName, Identity, userPrincipalName, TargetResourceDisplayName, Url
  | extend AccountName = tostring(split(userPrincipalName, "@")[0]), AccountUPNSuffix = tostring(split(userPrincipalName, "@")[1])
  | extend HostName = tostring(split(TargetResourceDisplayName, ".")[0]), DomainIndex = toint(indexof(TargetResourceDisplayName, '.'))
  | extend HostNameDomain = iff(DomainIndex != -1, substring(TargetResourceDisplayName, DomainIndex + 1), TargetResourceDisplayName)  
triggerOperator: gt

{
  "$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/712fab52-2a7d-401e-a08c-ff939cc7c25e')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/712fab52-2a7d-401e-a08c-ff939cc7c25e')]",
      "properties": {
        "alertRuleTemplateName": "712fab52-2a7d-401e-a08c-ff939cc7c25e",
        "customDetails": null,
        "description": "'This query identifies any URL indicators of compromise (IOCs) from threat intelligence (TI) by searching for matches in AuditLogs.'\n",
        "displayName": "TI Map URL Entity to AuditLogs",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "userPrincipalName",
                "identifier": "FullName"
              },
              {
                "columnName": "AccountName",
                "identifier": "Name"
              },
              {
                "columnName": "AccountUPNSuffix",
                "identifier": "UPNSuffix"
              }
            ]
          },
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "TargetResourceDisplayName",
                "identifier": "FullName"
              },
              {
                "columnName": "HostName",
                "identifier": "HostName"
              },
              {
                "columnName": "HostNameDomain",
                "identifier": "DnsDomain"
              }
            ]
          },
          {
            "entityType": "URL",
            "fieldMappings": [
              {
                "columnName": "Url",
                "identifier": "Url"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/URLEntity_AuditLogs.yaml",
        "query": "let dt_lookBack = 1h;\nlet ioc_lookBack = 14d;\nlet AuditEvents = materialize(AuditLogs\n  | where TimeGenerated >= ago(dt_lookBack)\n  // Extract the URL that is contained within the JSON data\n  | extend Url = extract(\"(http[s]?://(?:[a-zA-Z]|[0-9]|[$-_@.&+]|[!*\\\\(\\\\),]|(?:%[0-9a-fA-F][0-9a-fA-F]))+)\", 1,tostring(TargetResources))\n  | where isnotempty(Url)\n  | extend userPrincipalName = tostring(parse_json(tostring(InitiatedBy.user)).userPrincipalName)\n  | extend TargetResourceDisplayName = tostring(TargetResources[0].displayName)\n  | extend Audit_TimeGenerated = TimeGenerated);\nlet AuditUrls = AuditEvents | distinct Url = tolower(Url) | summarize make_list(Url);\nThreatIntelligenceIndicator\n| where isnotempty(Url)\n| where TimeGenerated >= ago(ioc_lookBack)\n| where tolower(Url) in (AuditUrls)\n| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId\n| where Active == true and ExpirationDateTime > now()\n| where Description !contains_cs \"State: inactive;\" and Description !contains_cs \"State: falsepos;\"\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 (AuditEvents) on Url\n| where Audit_TimeGenerated < ExpirationDateTime\n| summarize Audit_TimeGenerated = arg_max(Audit_TimeGenerated, *) by IndicatorId, Url\n| project Audit_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore,\nOperationName, Identity, userPrincipalName, TargetResourceDisplayName, Url\n| extend AccountName = tostring(split(userPrincipalName, \"@\")[0]), AccountUPNSuffix = tostring(split(userPrincipalName, \"@\")[1])\n| extend HostName = tostring(split(TargetResourceDisplayName, \".\")[0]), DomainIndex = toint(indexof(TargetResourceDisplayName, '.'))\n| extend HostNameDomain = iff(DomainIndex != -1, substring(TargetResourceDisplayName, DomainIndex + 1), TargetResourceDisplayName)\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "P14D",
        "severity": "Medium",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "CommandAndControl"
        ],
        "techniques": [
          "T1071"
        ],
        "templateVersion": "1.2.8",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}