TI Map URL Entity to Syslog Data

let dt_lookBack = 1h;
let ioc_lookBack = 14d;
ThreatIntelligenceIndicator
// Picking up only IOC's that contain the entities we want
| where isnotempty(Url)
| where TimeGenerated >= ago(ioc_lookBack)
| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
| where Active == true and ExpirationDateTime > now()
// 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 (
  Syslog
  | where TimeGenerated >= ago(dt_lookBack)
  // Extract URL from the Syslog message but only take messages that include URLs
  | extend Url = extract("(http[s]?://(?:[a-zA-Z]|[0-9]|[$-_@.&+]|[!*\\(\\),]|(?:%[0-9a-fA-F][0-9a-fA-F]))+)", 1,SyslogMessage)
  | where isnotempty(Url)
  | extend Syslog_TimeGenerated = TimeGenerated
) on Url
| where Syslog_TimeGenerated < ExpirationDateTime
| summarize Syslog_TimeGenerated  = arg_max(Syslog_TimeGenerated , *) by IndicatorId, Url
| project timestamp = Syslog_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore, SyslogMessage, Computer, ProcessName, Url, HostIP

description: |
    'This query identifies any URL indicators of compromise (IOCs) from threat intelligence (TI) by searching for matches in Syslog data.'
id: b31037ea-6f68-4fbd-bab2-d0d0f44c2fcf
requiredDataConnectors:
- connectorId: Syslog
  dataTypes:
  - Syslog
- connectorId: ThreatIntelligence
  dataTypes:
  - ThreatIntelligenceIndicator
- connectorId: ThreatIntelligenceTaxii
  dataTypes:
  - ThreatIntelligenceIndicator
- connectorId: MicrosoftDefenderThreatIntelligence
  dataTypes:
  - ThreatIntelligenceIndicator
version: 1.2.6
relevantTechniques:
- T1071
tactics:
- CommandAndControl
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/URLEntity_Syslog.yaml
kind: Scheduled
severity: Medium
entityMappings:
- fieldMappings:
  - columnName: Computer
    identifier: HostName
  entityType: Host
- fieldMappings:
  - columnName: HostIP
    identifier: Address
  entityType: IP
- fieldMappings:
  - columnName: Url
    identifier: Url
  entityType: URL
triggerThreshold: 0
queryFrequency: 1h
queryPeriod: 14d
triggerOperator: gt
query: |
  let dt_lookBack = 1h;
  let ioc_lookBack = 14d;
  ThreatIntelligenceIndicator
  // Picking up only IOC's that contain the entities we want
  | where isnotempty(Url)
  | where TimeGenerated >= ago(ioc_lookBack)
  | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
  | where Active == true and ExpirationDateTime > now()
  // 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 (
    Syslog
    | where TimeGenerated >= ago(dt_lookBack)
    // Extract URL from the Syslog message but only take messages that include URLs
    | extend Url = extract("(http[s]?://(?:[a-zA-Z]|[0-9]|[$-_@.&+]|[!*\\(\\),]|(?:%[0-9a-fA-F][0-9a-fA-F]))+)", 1,SyslogMessage)
    | where isnotempty(Url)
    | extend Syslog_TimeGenerated = TimeGenerated
  ) on Url
  | where Syslog_TimeGenerated < ExpirationDateTime
  | summarize Syslog_TimeGenerated  = arg_max(Syslog_TimeGenerated , *) by IndicatorId, Url
  | project timestamp = Syslog_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore, SyslogMessage, Computer, ProcessName, Url, HostIP  
name: TI Map URL Entity to Syslog Data

{
  "$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/b31037ea-6f68-4fbd-bab2-d0d0f44c2fcf')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/b31037ea-6f68-4fbd-bab2-d0d0f44c2fcf')]",
      "properties": {
        "alertRuleTemplateName": "b31037ea-6f68-4fbd-bab2-d0d0f44c2fcf",
        "customDetails": null,
        "description": "'This query identifies any URL indicators of compromise (IOCs) from threat intelligence (TI) by searching for matches in Syslog data.'\n",
        "displayName": "TI Map URL Entity to Syslog Data",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "Computer",
                "identifier": "HostName"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "HostIP",
                "identifier": "Address"
              }
            ]
          },
          {
            "entityType": "URL",
            "fieldMappings": [
              {
                "columnName": "Url",
                "identifier": "Url"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/URLEntity_Syslog.yaml",
        "query": "let dt_lookBack = 1h;\nlet ioc_lookBack = 14d;\nThreatIntelligenceIndicator\n// Picking up only IOC's that contain the entities we want\n| where isnotempty(Url)\n| where TimeGenerated >= ago(ioc_lookBack)\n| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId\n| where Active == true and ExpirationDateTime > now()\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  Syslog\n  | where TimeGenerated >= ago(dt_lookBack)\n  // Extract URL from the Syslog message but only take messages that include URLs\n  | extend Url = extract(\"(http[s]?://(?:[a-zA-Z]|[0-9]|[$-_@.&+]|[!*\\\\(\\\\),]|(?:%[0-9a-fA-F][0-9a-fA-F]))+)\", 1,SyslogMessage)\n  | where isnotempty(Url)\n  | extend Syslog_TimeGenerated = TimeGenerated\n) on Url\n| where Syslog_TimeGenerated < ExpirationDateTime\n| summarize Syslog_TimeGenerated  = arg_max(Syslog_TimeGenerated , *) by IndicatorId, Url\n| project timestamp = Syslog_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore, SyslogMessage, Computer, ProcessName, Url, HostIP\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "P14D",
        "severity": "Medium",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "CommandAndControl"
        ],
        "techniques": [
          "T1071"
        ],
        "templateVersion": "1.2.6",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}