TI map IP entity to AppServiceHTTPLogs

let dt_lookBack = 1h; // Look back 1 hour for AppServiceHTTPLogs
let ioc_lookBack = 14d; // Look back 14 days for threat intelligence indicators
// Fetch threat intelligence indicators related to IP addresses
let IP_Indicators = ThreatIntelligenceIndicator
  // Filter out indicators without relevant IP address fields
  | where isnotempty(NetworkIP) or isnotempty(EmailSourceIpAddress) or isnotempty(NetworkDestinationIP) or isnotempty(NetworkSourceIP)
  | where TimeGenerated >= ago(ioc_lookBack)
  // Filtering out rows where the Confidence Score is less than 50 as they would not have an Alert Priority label. 
  | where ConfidenceScore > 50
  // Select the IP entity based on availability of different IP fields
  | extend TI_ipEntity = iff(isnotempty(NetworkIP), NetworkIP, NetworkDestinationIP)
  | extend TI_ipEntity = iff(isempty(TI_ipEntity) and isnotempty(NetworkSourceIP), NetworkSourceIP, TI_ipEntity)
  | extend TI_ipEntity = iff(isempty(TI_ipEntity) and isnotempty(EmailSourceIpAddress), EmailSourceIpAddress, TI_ipEntity)
  // Determine AlertPriority based on ConfidenceScore
  | extend AlertPriority = case(ConfidenceScore > 82, "High",
                                ConfidenceScore > 74, "Medium",
                                "Low")
  // Exclude local addresses using the ipv4_is_private operator and filtering out specific address prefixes
  | where ipv4_is_private(TI_ipEntity) == false and  TI_ipEntity !startswith "fe80" and TI_ipEntity !startswith "::" and TI_ipEntity !startswith "127."
  | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
  | where Active == true and ExpirationDateTime > now();
// Perform a join between IP indicators and AppServiceHTTPLogs to identify potential malicious activity
IP_Indicators
  // Use innerunique to keep performance fast and result set low, as we only need one match to indicate potential malicious activity that needs investigation
  | join kind=innerunique (
    AppServiceHTTPLogs | where TimeGenerated >= ago(dt_lookBack)
    | where isnotempty(CIp)
    | extend WebApp = split(_ResourceId, '/')[8]
    | extend AppService_TimeGenerated = TimeGenerated // Rename time column for clarity
  )
  on $left.TI_ipEntity == $right.CIp
  // Filter out logs that occurred after the expiration of the corresponding indicator
  | where AppService_TimeGenerated < ExpirationDateTime
  // Group the results by IndicatorId and CIp, and keep the log entry with the latest timestamp
  | summarize AppService_TimeGenerated = arg_max(AppService_TimeGenerated, *) by IndicatorId, CIp
  // Select the desired output fields
  | project AppService_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, Url, ExpirationDateTime, ConfidenceScore, TI_ipEntity, CsUsername, WebApp = split(_ResourceId, '/')[8], CIp, CsHost, NetworkIP, NetworkDestinationIP, NetworkSourceIP, EmailSourceIpAddress, _ResourceId, Type, AlertPriority
  // Extract hostname and DNS domain from the CsHost field
  | extend HostName = tostring(split(CsHost, '.', 0)[0]), DnsDomain = tostring(strcat_array(array_slice(split(CsHost, '.'), 1, -1), '.'))
  // Rename the timestamp field
  | extend timestamp = AppService_TimeGenerated

tactics:
- CommandAndControl
query: |
  let dt_lookBack = 1h; // Look back 1 hour for AppServiceHTTPLogs
  let ioc_lookBack = 14d; // Look back 14 days for threat intelligence indicators
  // Fetch threat intelligence indicators related to IP addresses
  let IP_Indicators = ThreatIntelligenceIndicator
    // Filter out indicators without relevant IP address fields
    | where isnotempty(NetworkIP) or isnotempty(EmailSourceIpAddress) or isnotempty(NetworkDestinationIP) or isnotempty(NetworkSourceIP)
    | where TimeGenerated >= ago(ioc_lookBack)
    // Filtering out rows where the Confidence Score is less than 50 as they would not have an Alert Priority label. 
    | where ConfidenceScore > 50
    // Select the IP entity based on availability of different IP fields
    | extend TI_ipEntity = iff(isnotempty(NetworkIP), NetworkIP, NetworkDestinationIP)
    | extend TI_ipEntity = iff(isempty(TI_ipEntity) and isnotempty(NetworkSourceIP), NetworkSourceIP, TI_ipEntity)
    | extend TI_ipEntity = iff(isempty(TI_ipEntity) and isnotempty(EmailSourceIpAddress), EmailSourceIpAddress, TI_ipEntity)
    // Determine AlertPriority based on ConfidenceScore
    | extend AlertPriority = case(ConfidenceScore > 82, "High",
                                  ConfidenceScore > 74, "Medium",
                                  "Low")
    // Exclude local addresses using the ipv4_is_private operator and filtering out specific address prefixes
    | where ipv4_is_private(TI_ipEntity) == false and  TI_ipEntity !startswith "fe80" and TI_ipEntity !startswith "::" and TI_ipEntity !startswith "127."
    | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
    | where Active == true and ExpirationDateTime > now();
  // Perform a join between IP indicators and AppServiceHTTPLogs to identify potential malicious activity
  IP_Indicators
    // Use innerunique to keep performance fast and result set low, as we only need one match to indicate potential malicious activity that needs investigation
    | join kind=innerunique (
      AppServiceHTTPLogs | where TimeGenerated >= ago(dt_lookBack)
      | where isnotempty(CIp)
      | extend WebApp = split(_ResourceId, '/')[8]
      | extend AppService_TimeGenerated = TimeGenerated // Rename time column for clarity
    )
    on $left.TI_ipEntity == $right.CIp
    // Filter out logs that occurred after the expiration of the corresponding indicator
    | where AppService_TimeGenerated < ExpirationDateTime
    // Group the results by IndicatorId and CIp, and keep the log entry with the latest timestamp
    | summarize AppService_TimeGenerated = arg_max(AppService_TimeGenerated, *) by IndicatorId, CIp
    // Select the desired output fields
    | project AppService_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, Url, ExpirationDateTime, ConfidenceScore, TI_ipEntity, CsUsername, WebApp = split(_ResourceId, '/')[8], CIp, CsHost, NetworkIP, NetworkDestinationIP, NetworkSourceIP, EmailSourceIpAddress, _ResourceId, Type, AlertPriority
    // Extract hostname and DNS domain from the CsHost field
    | extend HostName = tostring(split(CsHost, '.', 0)[0]), DnsDomain = tostring(strcat_array(array_slice(split(CsHost, '.'), 1, -1), '.'))
    // Rename the timestamp field
    | extend timestamp = AppService_TimeGenerated  
requiredDataConnectors:
- dataTypes:
  - ThreatIntelligenceIndicator
  connectorId: ThreatIntelligence
- dataTypes:
  - ThreatIntelligenceIndicator
  connectorId: ThreatIntelligenceTaxii
- dataTypes:
  - ThreatIntelligenceIndicator
  connectorId: MicrosoftDefenderThreatIntelligence
name: TI map IP entity to AppServiceHTTPLogs
alertDetailsOverride:
  alertSeverityColumnName: AlertPriority
queryPeriod: 14d
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/IPEntity_AppServiceHTTPLogs.yaml
triggerThreshold: 0
description: |
    Identifies a match in AppServiceHTTPLogs from any IP IOC from TI
version: 1.5.3
kind: Scheduled
queryFrequency: 1h
severity: Medium
entityMappings:
- entityType: Host
  fieldMappings:
  - identifier: HostName
    columnName: HostName
  - identifier: DnsDomain
    columnName: DnsDomain
- entityType: Account
  fieldMappings:
  - identifier: Name
    columnName: CsUsername
- entityType: IP
  fieldMappings:
  - identifier: Address
    columnName: CIp
- entityType: URL
  fieldMappings:
  - identifier: Url
    columnName: Url
- entityType: AzureResource
  fieldMappings:
  - identifier: ResourceId
    columnName: _ResourceId
triggerOperator: gt
id: f9949656-473f-4503-bf43-a9d9890f7d08
relevantTechniques:
- T1071