TI map File Hash to CommonSecurityLog Event

let dt_lookBack = 1h;
let ioc_lookBack = 14d;
let fileHashIndicators = ThreatIntelIndicators
//extract key part of kv pair
| extend IndicatorType = replace(@"\[|\]|\""", "", tostring(split(ObservableKey, ":", 0)))
| where isnotempty(IndicatorType) and IndicatorType == "file"
| extend FileHashType = replace("'", "", substring(ObservableKey, indexof(ObservableKey, "hashes.") + 7, strlen(ObservableKey) - indexof(ObservableKey, "hashes.") - 7))
| extend FileHashValue = toupper(ObservableValue)
| extend IndicatorId = tostring(split(Id, "--")[2])
| extend Url = iff(ObservableKey == "url:value", ObservableValue, "")
| where isnotempty(FileHashValue)
| where TimeGenerated >= ago(ioc_lookBack)
| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id
| where IsActive == true and ValidUntil > now();
// Handle matches against both lower case and uppercase versions of the hash:
(fileHashIndicators | extend  FileHashValue = tolower(FileHashValue)
| union (fileHashIndicators | extend FileHashValue = toupper(FileHashValue)))
| project-reorder *, FileHashType, FileHashValue, 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 | where TimeGenerated >= ago(dt_lookBack)
  | where isnotempty(FileHash)
  | extend CommonSecurityLog_TimeGenerated = TimeGenerated
  )
on $left.FileHashValue == $right.FileHash
| where CommonSecurityLog_TimeGenerated < ValidUntil
| summarize CommonSecurityLog_TimeGenerated = arg_max(CommonSecurityLog_TimeGenerated, *) by IndicatorId, FileHashValue
| extend Description = tostring(parse_json(Data).description)
| extend ActivityGroupNames = extract(@"ActivityGroup:(\S+)", 1, tostring(parse_json(Data).labels))
| extend Description = tostring(parse_json(Data).description)
| extend ActivityGroupNames = extract(@"ActivityGroup:(\S+)", 1, tostring(parse_json(Data).labels))
| project CommonSecurityLog_TimeGenerated, Description, ActivityGroupNames, Id, ValidUntil, Confidence,
SourceIP, SourcePort, DestinationIP, DestinationPort, SourceUserID, SourceUserName, DeviceName, DeviceAction,
RequestURL, DestinationUserName, DestinationUserID, ApplicationProtocol, Activity, FileHashValue, FileHashType, Url
| 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
triggerThreshold: 0
version: 1.3.7
triggerOperator: gt
requiredDataConnectors:
- dataTypes:
  - CommonSecurityLog
  connectorId: PaloAltoNetworks
- dataTypes:
  - ThreatIntelligenceIndicator
  connectorId: ThreatIntelligence
- dataTypes:
  - ThreatIntelligenceIndicator
  connectorId: ThreatIntelligenceTaxii
- dataTypes:
  - ThreatIntelligenceIndicator
  connectorId: MicrosoftDefenderThreatIntelligence
name: TI map File Hash to CommonSecurityLog Event
severity: Medium
queryPeriod: 14d
kind: Scheduled
description: |
    'Identifies a match in CommonSecurityLog Event data from any FileHash IOC from TI'
queryFrequency: 1h
tactics:
- CommandAndControl
query: |
  let dt_lookBack = 1h;
  let ioc_lookBack = 14d;
  let fileHashIndicators = ThreatIntelIndicators
  //extract key part of kv pair
  | extend IndicatorType = replace(@"\[|\]|\""", "", tostring(split(ObservableKey, ":", 0)))
  | where isnotempty(IndicatorType) and IndicatorType == "file"
  | extend FileHashType = replace("'", "", substring(ObservableKey, indexof(ObservableKey, "hashes.") + 7, strlen(ObservableKey) - indexof(ObservableKey, "hashes.") - 7))
  | extend FileHashValue = toupper(ObservableValue)
  | extend IndicatorId = tostring(split(Id, "--")[2])
  | extend Url = iff(ObservableKey == "url:value", ObservableValue, "")
  | where isnotempty(FileHashValue)
  | where TimeGenerated >= ago(ioc_lookBack)
  | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id
  | where IsActive == true and ValidUntil > now();
  // Handle matches against both lower case and uppercase versions of the hash:
  (fileHashIndicators | extend  FileHashValue = tolower(FileHashValue)
  | union (fileHashIndicators | extend FileHashValue = toupper(FileHashValue)))
  | project-reorder *, FileHashType, FileHashValue, 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 | where TimeGenerated >= ago(dt_lookBack)
    | where isnotempty(FileHash)
    | extend CommonSecurityLog_TimeGenerated = TimeGenerated
    )
  on $left.FileHashValue == $right.FileHash
  | where CommonSecurityLog_TimeGenerated < ValidUntil
  | summarize CommonSecurityLog_TimeGenerated = arg_max(CommonSecurityLog_TimeGenerated, *) by IndicatorId, FileHashValue
  | extend Description = tostring(parse_json(Data).description)
  | extend ActivityGroupNames = extract(@"ActivityGroup:(\S+)", 1, tostring(parse_json(Data).labels))
  | extend Description = tostring(parse_json(Data).description)
  | extend ActivityGroupNames = extract(@"ActivityGroup:(\S+)", 1, tostring(parse_json(Data).labels))
  | project CommonSecurityLog_TimeGenerated, Description, ActivityGroupNames, Id, ValidUntil, Confidence,
  SourceIP, SourcePort, DestinationIP, DestinationPort, SourceUserID, SourceUserName, DeviceName, DeviceAction,
  RequestURL, DestinationUserName, DestinationUserID, ApplicationProtocol, Activity, FileHashValue, FileHashType, Url
  | 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  
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence (NEW)/Analytic Rules/FileHashEntity_CommonSecurityLog.yaml
id: 432996e9-8a93-4407-985f-13707b318a0b
entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: SourceUserName
  - identifier: Name
    columnName: Name
  - identifier: UPNSuffix
    columnName: UPNSuffix
  entityType: Account
- fieldMappings:
  - identifier: FullName
    columnName: DeviceName
  - identifier: HostName
    columnName: HostName
  - identifier: DnsDomain
    columnName: DnsDomain
  entityType: Host
- fieldMappings:
  - identifier: Address
    columnName: SourceIP
  entityType: IP
- fieldMappings:
  - identifier: Url
    columnName: Url
  entityType: URL
- fieldMappings:
  - identifier: Value
    columnName: FileHashValue
  - identifier: Algorithm
    columnName: FileHashType
  entityType: FileHash

{
  "$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/432996e9-8a93-4407-985f-13707b318a0b')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/432996e9-8a93-4407-985f-13707b318a0b')]",
      "properties": {
        "alertRuleTemplateName": "432996e9-8a93-4407-985f-13707b318a0b",
        "customDetails": null,
        "description": "'Identifies a match in CommonSecurityLog Event data from any FileHash IOC from TI'\n",
        "displayName": "TI map File Hash to CommonSecurityLog Event",
        "enabled": true,
        "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"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence (NEW)/Analytic Rules/FileHashEntity_CommonSecurityLog.yaml",
        "query": "let dt_lookBack = 1h;\nlet ioc_lookBack = 14d;\nlet fileHashIndicators = ThreatIntelIndicators\n//extract key part of kv pair\n| extend IndicatorType = replace(@\"\\[|\\]|\\\"\"\", \"\", tostring(split(ObservableKey, \":\", 0)))\n| where isnotempty(IndicatorType) and IndicatorType == \"file\"\n| extend FileHashType = replace(\"'\", \"\", substring(ObservableKey, indexof(ObservableKey, \"hashes.\") + 7, strlen(ObservableKey) - indexof(ObservableKey, \"hashes.\") - 7))\n| extend FileHashValue = toupper(ObservableValue)\n| extend IndicatorId = tostring(split(Id, \"--\")[2])\n| extend Url = iff(ObservableKey == \"url:value\", ObservableValue, \"\")\n| where isnotempty(FileHashValue)\n| where TimeGenerated >= ago(ioc_lookBack)\n| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id\n| where IsActive == true and ValidUntil > now();\n// Handle matches against both lower case and uppercase versions of the hash:\n(fileHashIndicators | extend  FileHashValue = tolower(FileHashValue)\n| union (fileHashIndicators | extend FileHashValue = toupper(FileHashValue)))\n| project-reorder *, FileHashType, FileHashValue, Type\n// 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\n|  join kind=innerunique (\n  CommonSecurityLog | where TimeGenerated >= ago(dt_lookBack)\n  | where isnotempty(FileHash)\n  | extend CommonSecurityLog_TimeGenerated = TimeGenerated\n  )\non $left.FileHashValue == $right.FileHash\n| where CommonSecurityLog_TimeGenerated < ValidUntil\n| summarize CommonSecurityLog_TimeGenerated = arg_max(CommonSecurityLog_TimeGenerated, *) by IndicatorId, FileHashValue\n| extend Description = tostring(parse_json(Data).description)\n| extend ActivityGroupNames = extract(@\"ActivityGroup:(\\S+)\", 1, tostring(parse_json(Data).labels))\n| extend Description = tostring(parse_json(Data).description)\n| extend ActivityGroupNames = extract(@\"ActivityGroup:(\\S+)\", 1, tostring(parse_json(Data).labels))\n| project CommonSecurityLog_TimeGenerated, Description, ActivityGroupNames, Id, ValidUntil, Confidence,\nSourceIP, SourcePort, DestinationIP, DestinationPort, SourceUserID, SourceUserName, DeviceName, DeviceAction,\nRequestURL, DestinationUserName, DestinationUserID, ApplicationProtocol, Activity, FileHashValue, FileHashType, Url\n| extend HostName = tostring(split(DeviceName, '.', 0)[0]), DnsDomain = tostring(strcat_array(array_slice(split(DeviceName, '.'), 1, -1), '.'))\n| extend Name = tostring(split(SourceUserName, '@', 0)[0]), UPNSuffix = tostring(split(SourceUserName, '@', 1)[0])\n| extend timestamp = CommonSecurityLog_TimeGenerated\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "P14D",
        "severity": "Medium",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "CommandAndControl"
        ],
        "techniques": [
          "T1071"
        ],
        "templateVersion": "1.3.7",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}