TI map File Hash to CommonSecurityLog Event

let dt_lookBack = 1h;
let ioc_lookBack = 14d;
let fileHashIndicators = ThreatIntelligenceIndicator
| where isnotempty(FileHashValue)
| where TimeGenerated >= ago(ioc_lookBack)
| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
| where Active == true and ExpirationDateTime > now();
// Handle matches against both lower case and uppercase versions of the hash:
(fileHashIndicators | extend  FileHashValue = tolower(FileHashValue)
| union (fileHashIndicators | extend FileHashValue = toupper(FileHashValue)))
// 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 | where TimeGenerated >= ago(dt_lookBack)
  | where isnotempty(FileHash)
  | extend CommonSecurityLog_TimeGenerated = TimeGenerated
  )
on $left.FileHashValue == $right.FileHash
| where CommonSecurityLog_TimeGenerated < ExpirationDateTime
| summarize CommonSecurityLog_TimeGenerated = arg_max(CommonSecurityLog_TimeGenerated, *) by IndicatorId, FileHashValue
| project CommonSecurityLog_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, Url, ExpirationDateTime, ConfidenceScore,
SourceIP, SourcePort, DestinationIP, DestinationPort, SourceUserID, SourceUserName, DeviceName, DeviceAction,
RequestURL, DestinationUserName, DestinationUserID, ApplicationProtocol, Activity, FileHashValue, FileHashType
| extend HostName = tostring(split(DeviceName, '.', 0)[0]), DnsDomain = tostring(strcat_array(array_slice(split(DeviceName, '.'), 1, -1), '.'))
| extend Name = tostring(split(SourceUserName, '@', 0)[0]), UPNSuffix = tostring(split(SourceUserName, '@', 1)[0])
| extend timestamp = CommonSecurityLog_TimeGenerated

relevantTechniques:
- T1071
entityMappings:
- entityType: Account
  fieldMappings:
  - columnName: SourceUserName
    identifier: FullName
  - columnName: Name
    identifier: Name
  - columnName: UPNSuffix
    identifier: UPNSuffix
- entityType: Host
  fieldMappings:
  - columnName: DeviceName
    identifier: FullName
  - columnName: HostName
    identifier: HostName
  - columnName: DnsDomain
    identifier: DnsDomain
- entityType: IP
  fieldMappings:
  - columnName: SourceIP
    identifier: Address
- entityType: URL
  fieldMappings:
  - columnName: Url
    identifier: Url
- entityType: FileHash
  fieldMappings:
  - columnName: FileHashValue
    identifier: Value
  - columnName: FileHashType
    identifier: Algorithm
version: 1.3.6
id: 5d33fc63-b83b-4913-b95e-94d13f0d379f
severity: Medium
kind: Scheduled
queryFrequency: 1h
description: |
    'Identifies a match in CommonSecurityLog Event data from any FileHash IOC from TI'
requiredDataConnectors:
- connectorId: PaloAltoNetworks
  dataTypes:
  - CommonSecurityLog
- connectorId: ThreatIntelligence
  dataTypes:
  - ThreatIntelligenceIndicator
- connectorId: ThreatIntelligenceTaxii
  dataTypes:
  - ThreatIntelligenceIndicator
- connectorId: MicrosoftDefenderThreatIntelligence
  dataTypes:
  - ThreatIntelligenceIndicator
triggerOperator: gt
name: TI map File Hash to CommonSecurityLog Event
tactics:
- CommandAndControl
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/FileHashEntity_CommonSecurityLog.yaml
triggerThreshold: 0
queryPeriod: 14d
query: |
  let dt_lookBack = 1h;
  let ioc_lookBack = 14d;
  let fileHashIndicators = ThreatIntelligenceIndicator
  | where isnotempty(FileHashValue)
  | where TimeGenerated >= ago(ioc_lookBack)
  | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
  | where Active == true and ExpirationDateTime > now();
  // Handle matches against both lower case and uppercase versions of the hash:
  (fileHashIndicators | extend  FileHashValue = tolower(FileHashValue)
  | union (fileHashIndicators | extend FileHashValue = toupper(FileHashValue)))
  // 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 | where TimeGenerated >= ago(dt_lookBack)
    | where isnotempty(FileHash)
    | extend CommonSecurityLog_TimeGenerated = TimeGenerated
    )
  on $left.FileHashValue == $right.FileHash
  | where CommonSecurityLog_TimeGenerated < ExpirationDateTime
  | summarize CommonSecurityLog_TimeGenerated = arg_max(CommonSecurityLog_TimeGenerated, *) by IndicatorId, FileHashValue
  | project CommonSecurityLog_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, Url, ExpirationDateTime, ConfidenceScore,
  SourceIP, SourcePort, DestinationIP, DestinationPort, SourceUserID, SourceUserName, DeviceName, DeviceAction,
  RequestURL, DestinationUserName, DestinationUserID, ApplicationProtocol, Activity, FileHashValue, FileHashType
  | extend HostName = tostring(split(DeviceName, '.', 0)[0]), DnsDomain = tostring(strcat_array(array_slice(split(DeviceName, '.'), 1, -1), '.'))
  | extend Name = tostring(split(SourceUserName, '@', 0)[0]), UPNSuffix = tostring(split(SourceUserName, '@', 1)[0])
  | extend timestamp = CommonSecurityLog_TimeGenerated