Solutions/Threat Intelligence (NEW)/Analytic Rules/URLEntity_PaloAlto.yaml

id: 32b437c4-dddb-45b3-9aae-5188e80624b0
name: TI Map URL Entity to PaloAlto Data
description: |
  'This query identifies any URL indicators of compromise (IOCs) from threat intelligence (TI) by searching for matches in PaloAlto Data.'
severity: Medium
requiredDataConnectors:
  - connectorId: PaloAltoNetworks
    dataTypes:
      - CommonSecurityLog
  - connectorId: ThreatIntelligence
    dataTypes:
      - ThreatIntelligenceIndicator
  - connectorId: ThreatIntelligenceTaxii
    dataTypes:
      - ThreatIntelligenceIndicator
  - connectorId: MicrosoftDefenderThreatIntelligence
    dataTypes:
      - ThreatIntelligenceIndicator
queryFrequency: 1h
queryPeriod: 14d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - CommandAndControl
relevantTechniques:
  - T1071
query: |
  let dt_lookBack = 1h;
  let ioc_lookBack = 14d;
  ThreatIntelIndicators
  //extract key part of kv pair
  | extend IndicatorType = replace(@"\[|\]|\""", "", tostring(split(ObservableKey, ":", 0)))
  | where IndicatorType == "url"
  | extend Url = ObservableValue
  | where isnotempty(Url)
  | extend TrafficLightProtocolLevel = tostring(parse_json(AdditionalFields).TLPLevel)
  // 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 Id
  | where IsActive == true and ValidUntil > now()
     | project-reorder *, Tags, TrafficLightProtocolLevel, Url, Type
  // 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 (
    CommonSecurityLog
    | extend IngestionTime = ingestion_time()
    | where IngestionTime > ago(dt_lookBack)
    // Select on Palo Alto logs
    | where DeviceVendor =~ "Palo Alto Networks"
    | where DeviceEventClassID =~ 'url'
    //Uncomment the line below to only alert on allowed connections
    //| where DeviceAction !~ "block-url"
    //Select logs where URL data is populated
    | extend PA_Url = column_ifexists("RequestURL", "None")
    | extend PA_Url = iif(isempty(PA_Url), extract("([^\"]+)", 1, tolower(AdditionalExtensions)), trim('"', PA_Url))
    | extend PA_Url = iif(PA_Url !startswith "http://" and ApplicationProtocol !~ "ssl", strcat('http://', PA_Url), iif(PA_Url !startswith "https://" and ApplicationProtocol =~ "ssl", strcat('https://', PA_Url), PA_Url))
    | where isnotempty(PA_Url)
    | extend CommonSecurityLog_TimeGenerated = TimeGenerated
  ) on $left.Url == $right.PA_Url
  | where CommonSecurityLog_TimeGenerated < ValidUntil
  | extend Description = tostring(parse_json(Data).description)
  | extend ActivityGroupNames = extract(@"ActivityGroup:(\S+)", 1, tostring(parse_json(Data).labels))
  | summarize CommonSecurityLog_TimeGenerated = arg_max(CommonSecurityLog_TimeGenerated, *) by Id, PA_Url
  | project timestamp = CommonSecurityLog_TimeGenerated, Description, ActivityGroupNames, Id, Type, ValidUntil, Confidence, DeviceAction, SourceIP, PA_Url, DeviceName
entityMappings:
  - entityType: Host
    fieldMappings:
      - identifier: HostName
        columnName: DeviceName
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: SourceIP
  - entityType: URL
    fieldMappings:
      - identifier: Url
        columnName: PA_Url
version: 1.2.5
kind: Scheduled