PRODAFT USTA - TI map URL to Syslog

let dt_lookBack = 1h;
let ioc_lookBack = 14d;
ThreatIntelIndicators
// Each USTA IoC feed uploads under its own SourceSystem ("PRODAFT USTA - Malicious URLs", etc.)
| where SourceSystem startswith "PRODAFT USTA"
// ObservableKey is a STIX kv pair ("url:value") - take the type before the colon
| extend IndicatorType = replace(@"\[|\]|\""", "", tostring(split(ObservableKey, ":", 0)))
| where IndicatorType == "url"
| extend Url = ObservableValue
| extend TrafficLightProtocolLevel = tostring(parse_json(AdditionalFields).TLPLevel)
| where TimeGenerated >= ago(ioc_lookBack)
| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id, ObservableValue
| where IsActive and (ValidUntil > now() or isempty(ValidUntil))
| project-reorder *, Tags, TrafficLightProtocolLevel, Url, Type
// innerunique: one match per indicator is enough to alert, and it keeps the join cheap
| join kind=innerunique (
  Syslog
  | where TimeGenerated >= ago(dt_lookBack)
  // Pull the first URL out of the free-text message; rows without one drop out of the join
  | extend Url = extract("(http[s]?://(?:[a-zA-Z]|[0-9]|[$-_@.&+]|[!*\\(\\),]|(?:%[0-9a-fA-F][0-9a-fA-F]))+)", 1,SyslogMessage)
  | extend Syslog_TimeGenerated = TimeGenerated
) on Url
// non-expiring indicators are allowed above, so they must survive this filter too
| where isempty(ValidUntil) or Syslog_TimeGenerated < ValidUntil
| summarize Syslog_TimeGenerated  = arg_max(Syslog_TimeGenerated , *) by Id, Url
| extend Description = tostring(parse_json(Data).description)
| extend IndicatorTags = tostring(parse_json(Data).labels)
| project timestamp = Syslog_TimeGenerated, Description, IndicatorTags, Id, Type, ValidUntil, Confidence, SyslogMessage, Computer, ProcessName, Url, HostIP

name: PRODAFT USTA - TI map URL to Syslog
triggerOperator: gt
query: |
  let dt_lookBack = 1h;
  let ioc_lookBack = 14d;
  ThreatIntelIndicators
  // Each USTA IoC feed uploads under its own SourceSystem ("PRODAFT USTA - Malicious URLs", etc.)
  | where SourceSystem startswith "PRODAFT USTA"
  // ObservableKey is a STIX kv pair ("url:value") - take the type before the colon
  | extend IndicatorType = replace(@"\[|\]|\""", "", tostring(split(ObservableKey, ":", 0)))
  | where IndicatorType == "url"
  | extend Url = ObservableValue
  | extend TrafficLightProtocolLevel = tostring(parse_json(AdditionalFields).TLPLevel)
  | where TimeGenerated >= ago(ioc_lookBack)
  | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id, ObservableValue
  | where IsActive and (ValidUntil > now() or isempty(ValidUntil))
  | project-reorder *, Tags, TrafficLightProtocolLevel, Url, Type
  // innerunique: one match per indicator is enough to alert, and it keeps the join cheap
  | join kind=innerunique (
    Syslog
    | where TimeGenerated >= ago(dt_lookBack)
    // Pull the first URL out of the free-text message; rows without one drop out of the join
    | extend Url = extract("(http[s]?://(?:[a-zA-Z]|[0-9]|[$-_@.&+]|[!*\\(\\),]|(?:%[0-9a-fA-F][0-9a-fA-F]))+)", 1,SyslogMessage)
    | extend Syslog_TimeGenerated = TimeGenerated
  ) on Url
  // non-expiring indicators are allowed above, so they must survive this filter too
  | where isempty(ValidUntil) or Syslog_TimeGenerated < ValidUntil
  | summarize Syslog_TimeGenerated  = arg_max(Syslog_TimeGenerated , *) by Id, Url
  | extend Description = tostring(parse_json(Data).description)
  | extend IndicatorTags = tostring(parse_json(Data).labels)
  | project timestamp = Syslog_TimeGenerated, Description, IndicatorTags, Id, Type, ValidUntil, Confidence, SyslogMessage, Computer, ProcessName, Url, HostIP
queryFrequency: 1h
description: |
  'Identifies a match in Syslog data from any malicious URL indicator ingested from PRODAFT
  USTA IoC Threat Intelligence (SourceSystem starting with "PRODAFT USTA").'
id: 99ae4d06-d352-4926-a1d7-9c28e25b1313
triggerThreshold: 0
queryPeriod: 14d
version: 1.0.0
kind: Scheduled
relevantTechniques:
- T1071
severity: Medium
requiredDataConnectors:
- connectorId: Syslog
  dataTypes:
  - Syslog
- connectorId: PRODAFTUstaIoCUploadIndicators
  dataTypes:
  - ThreatIntelIndicators
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/PRODAFT%20USTA%20-%20IoC%20Threat%20Intelligence/Analytic%20Rules/TIMapUrlToSyslog.yaml
tactics:
- CommandAndControl
entityMappings:
- fieldMappings:
  - identifier: HostName
    columnName: Computer
  entityType: Host
- fieldMappings:
  - identifier: Address
    columnName: HostIP
  entityType: IP
- fieldMappings:
  - identifier: Url
    columnName: Url
  entityType: URL

{
  "$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/99ae4d06-d352-4926-a1d7-9c28e25b1313')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/99ae4d06-d352-4926-a1d7-9c28e25b1313')]",
      "properties": {
        "alertRuleTemplateName": "99ae4d06-d352-4926-a1d7-9c28e25b1313",
        "customDetails": null,
        "description": "'Identifies a match in Syslog data from any malicious URL indicator ingested from PRODAFT\nUSTA IoC Threat Intelligence (SourceSystem starting with \"PRODAFT USTA\").'\n",
        "displayName": "PRODAFT USTA - TI map URL to Syslog",
        "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/PRODAFT%20USTA%20-%20IoC%20Threat%20Intelligence/Analytic%20Rules/TIMapUrlToSyslog.yaml",
        "query": "let dt_lookBack = 1h;\nlet ioc_lookBack = 14d;\nThreatIntelIndicators\n// Each USTA IoC feed uploads under its own SourceSystem (\"PRODAFT USTA - Malicious URLs\", etc.)\n| where SourceSystem startswith \"PRODAFT USTA\"\n// ObservableKey is a STIX kv pair (\"url:value\") - take the type before the colon\n| extend IndicatorType = replace(@\"\\[|\\]|\\\"\"\", \"\", tostring(split(ObservableKey, \":\", 0)))\n| where IndicatorType == \"url\"\n| extend Url = ObservableValue\n| extend TrafficLightProtocolLevel = tostring(parse_json(AdditionalFields).TLPLevel)\n| where TimeGenerated >= ago(ioc_lookBack)\n| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id, ObservableValue\n| where IsActive and (ValidUntil > now() or isempty(ValidUntil))\n| project-reorder *, Tags, TrafficLightProtocolLevel, Url, Type\n// innerunique: one match per indicator is enough to alert, and it keeps the join cheap\n| join kind=innerunique (\n  Syslog\n  | where TimeGenerated >= ago(dt_lookBack)\n  // Pull the first URL out of the free-text message; rows without one drop out of the join\n  | extend Url = extract(\"(http[s]?://(?:[a-zA-Z]|[0-9]|[$-_@.&+]|[!*\\\\(\\\\),]|(?:%[0-9a-fA-F][0-9a-fA-F]))+)\", 1,SyslogMessage)\n  | extend Syslog_TimeGenerated = TimeGenerated\n) on Url\n// non-expiring indicators are allowed above, so they must survive this filter too\n| where isempty(ValidUntil) or Syslog_TimeGenerated < ValidUntil\n| summarize Syslog_TimeGenerated  = arg_max(Syslog_TimeGenerated , *) by Id, Url\n| extend Description = tostring(parse_json(Data).description)\n| extend IndicatorTags = tostring(parse_json(Data).labels)\n| project timestamp = Syslog_TimeGenerated, Description, IndicatorTags, Id, Type, ValidUntil, Confidence, SyslogMessage, Computer, ProcessName, Url, HostIP\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "P14D",
        "severity": "Medium",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "CommandAndControl"
        ],
        "techniques": [
          "T1071"
        ],
        "templateVersion": "1.0.0",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}