TI Map URL Entity to Syslog Data

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Id	b31037ea-6f68-4fbd-bab2-d0d0f44c2fcf
Rulename	TI Map URL Entity to Syslog Data
Description	This query identifies any URL indicators of compromise (IOCs) from threat intelligence (TI) by searching for matches in Syslog data.
Severity	Medium
Tactics	Impact
Required data connectors	MicrosoftDefenderThreatIntelligence Syslog ThreatIntelligence ThreatIntelligenceTaxii
Kind	Scheduled
Query frequency	1h
Query period	14d
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/URLEntity_Syslog.yaml
Version	1.2.5
Arm template	b31037ea-6f68-4fbd-bab2-d0d0f44c2fcf.json

KQL

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

YAML

severity: Medium
queryFrequency: 1h
kind: Scheduled
version: 1.2.5
triggerOperator: gt
description: |
    'This query identifies any URL indicators of compromise (IOCs) from threat intelligence (TI) by searching for matches in Syslog data.'
queryPeriod: 14d
id: b31037ea-6f68-4fbd-bab2-d0d0f44c2fcf
entityMappings:
- entityType: Host
  fieldMappings:
  - columnName: Computer
    identifier: HostName
- entityType: IP
  fieldMappings:
  - columnName: HostIP
    identifier: Address
- entityType: URL
  fieldMappings:
  - columnName: Url
    identifier: Url
tactics:
- Impact
name: TI Map URL Entity to Syslog Data
triggerThreshold: 0
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/URLEntity_Syslog.yaml
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  
requiredDataConnectors:
- dataTypes:
  - Syslog
  connectorId: Syslog
- dataTypes:
  - ThreatIntelligenceIndicator
  connectorId: ThreatIntelligence
- dataTypes:
  - ThreatIntelligenceIndicator
  connectorId: ThreatIntelligenceTaxii
- dataTypes:
  - ThreatIntelligenceIndicator
  connectorId: MicrosoftDefenderThreatIntelligence

ARM

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2023-02-01-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",
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Impact"
        ],
        "templateVersion": "1.2.5",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}