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

id: 9e32e545-e60c-47de-9941-f9ca1ada0a42
name: TI Map URL Entity to EmailUrlInfo
description: |
  'This query identifies any URL indicators of compromise (IOCs) from threat intelligence (TI) by searching for matches in EmailUrlInfo.'
severity: Medium
requiredDataConnectors:
  - connectorId: AzureActiveDirectory
    dataTypes:
      - EmailUrlInfo
  - 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;
  let EmailUrlInfo_ = materialize(EmailUrlInfo
      | where isnotempty(Url)
      | where TimeGenerated >= ago(dt_lookBack)
      | extend Url = tolower(Url)
      | extend EmailUrlInfo_TimeGenerated = TimeGenerated);
  let EmailUrls = EmailUrlInfo_ | distinct Url | summarize make_list(Url);
  let EmailUrlDomains = EmailUrlInfo_ | distinct UrlDomain | summarize make_list(UrlDomain);
  let EmailEvents_ = materialize(EmailEvents
      | where TimeGenerated >= ago(dt_lookBack));
  let TI = materialize(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)
  | extend IndicatorId = tostring(split(Id, "--")[2])
      | where TimeGenerated >= ago(ioc_lookBack)
      | where (isnotempty(Url) or isnotempty(Url)) 
      | where tolower(Url) in (EmailUrls) or tolower(Url) in (EmailUrlDomains)
      | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id
      | where IsActive == true and ValidUntil > now());
  (union
      (TI | join kind=innerunique (EmailUrlInfo_) on Url),
      (TI | join kind=innerunique (EmailUrlInfo_) on $left.Url == $right.UrlDomain))
  | where EmailUrlInfo_TimeGenerated < ValidUntil
  | summarize EmailUrlInfo_TimeGenerated = arg_max(EmailUrlInfo_TimeGenerated, *) by IndicatorId, Url
  | extend Description = tostring(parse_json(Data).description)
  | extend ActivityGroupNames = extract(@"ActivityGroup:(\S+)", 1, tostring(parse_json(Data).labels))
  | project EmailUrlInfo_TimeGenerated, Description, ActivityGroupNames, IndicatorId, Type, ValidUntil, Confidence, Url, UrlDomain, UrlLocation, NetworkMessageId
  | extend timestamp = EmailUrlInfo_TimeGenerated
  | join kind=inner (EmailEvents_) on NetworkMessageId
  | where DeliveryAction !has "Blocked"
  | extend Name = tostring(split(RecipientEmailAddress, '@', 0)[0]), UPNSuffix = tostring(split(RecipientEmailAddress, '@', 1)[0])
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: RecipientEmailAddress
      - identifier: Name
        columnName: Name
      - identifier: UPNSuffix
        columnName: UPNSuffix
  - entityType: URL
    fieldMappings:
      - identifier: Url
        columnName: Url
version: 1.0.2
kind: Scheduled