Unusual identity creation using exchange powershell | Microsoft Sentinel Analytic Rules

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Id	0a3f4f4f-46ad-4562-acd6-f17730a5aef4
Rulename	Unusual identity creation using exchange powershell
Description	The query below identifies creation of unusual identity by the Europium actor to mimic Microsoft Exchange Health Manager Service account using Exchange PowerShell commands Reference: https://www.microsoft.com/security/blog/2022/09/08/microsoft-investigates-iranian-attacks-against-the-albanian-government/
Severity	High
Tactics	Persistence
Techniques	T1136
Required data connectors	MicrosoftThreatProtection SecurityEvents
Kind	Scheduled
Query frequency	12h
Query period	12h
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Detections/MultipleDataSources/EuropiumUnusualIdentity.yaml
Version	1.1.1
Arm template	0a3f4f4f-46ad-4562-acd6-f17730a5aef4.json

KQL

(union isfuzzy=true
(SecurityEvent
| where EventID==4688
| where CommandLine has_any ("New-Mailbox","Update-RoleGroupMember") and CommandLine has "HealthMailbox55x2yq"
| project TimeGenerated, DeviceName = Computer, AccountName = SubjectUserName, AccountDomain = SubjectDomainName, ProcessName, ProcessNameFullPath = NewProcessName, EventID, Activity, CommandLine, EventSourceName, Type
| extend InitiatingProcessAccount = strcat(AccountDomain, "\\", AccountName)
),
(DeviceProcessEvents
| where ProcessCommandLine has_any ("New-Mailbox","Update-RoleGroupMember") and ProcessCommandLine has "HealthMailbox55x2yq"
| extend timestamp = TimeGenerated, AccountDomain = InitiatingProcessAccountDomain, AccountName = InitiatingProcessAccountName
| extend InitiatingProcessAccount = strcat(AccountDomain, "\\", AccountName)
)
)
| extend HostName = tostring(split(DeviceName, ".")[0]), DomainIndex = toint(indexof(DeviceName, '.'))
| extend HostNameDomain = iff(DomainIndex != -1, substring(DeviceName, DomainIndex + 1), DeviceName)

YAML

name: Unusual identity creation using exchange powershell
triggerOperator: gt
query: |
  (union isfuzzy=true
  (SecurityEvent
  | where EventID==4688
  | where CommandLine has_any ("New-Mailbox","Update-RoleGroupMember") and CommandLine has "HealthMailbox55x2yq"
  | project TimeGenerated, DeviceName = Computer, AccountName = SubjectUserName, AccountDomain = SubjectDomainName, ProcessName, ProcessNameFullPath = NewProcessName, EventID, Activity, CommandLine, EventSourceName, Type
  | extend InitiatingProcessAccount = strcat(AccountDomain, "\\", AccountName)
  ),
  (DeviceProcessEvents
  | where ProcessCommandLine has_any ("New-Mailbox","Update-RoleGroupMember") and ProcessCommandLine has "HealthMailbox55x2yq"
  | extend timestamp = TimeGenerated, AccountDomain = InitiatingProcessAccountDomain, AccountName = InitiatingProcessAccountName
  | extend InitiatingProcessAccount = strcat(AccountDomain, "\\", AccountName)
  )
  )
  | extend HostName = tostring(split(DeviceName, ".")[0]), DomainIndex = toint(indexof(DeviceName, '.'))
  | extend HostNameDomain = iff(DomainIndex != -1, substring(DeviceName, DomainIndex + 1), DeviceName)
queryFrequency: 12h
description: |
  ' The query below identifies creation of unusual identity by the Europium actor to mimic Microsoft Exchange Health Manager Service account using Exchange PowerShell commands
    Reference: https://www.microsoft.com/security/blog/2022/09/08/microsoft-investigates-iranian-attacks-against-the-albanian-government/'
id: 0a3f4f4f-46ad-4562-acd6-f17730a5aef4
triggerThreshold: 0
queryPeriod: 12h
version: 1.1.1
kind: Scheduled
relevantTechniques:
- T1136
tags:
- Europium
severity: High
requiredDataConnectors:
- connectorId: SecurityEvents
  dataTypes:
  - SecurityEvent
- connectorId: MicrosoftThreatProtection
  dataTypes:
  - DeviceProcessEvents
metadata:
  categories:
    domains:
    - Security - Threat Protection
    - Identity
  support:
    tier: Community
  author:
    name: Microsoft Security Research
  source:
    kind: Community
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/MultipleDataSources/EuropiumUnusualIdentity.yaml
tactics:
- Persistence
entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: InitiatingProcessAccount
  - identifier: Name
    columnName: AccountName
  - identifier: NTDomain
    columnName: AccountDomain
  entityType: Account
- fieldMappings:
  - identifier: FullName
    columnName: DeviceName
  - identifier: HostName
    columnName: HostName
  - identifier: NTDomain
    columnName: HostNameDomain
  entityType: Host

ARM

{
  "$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/0a3f4f4f-46ad-4562-acd6-f17730a5aef4')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/0a3f4f4f-46ad-4562-acd6-f17730a5aef4')]",
      "properties": {
        "alertRuleTemplateName": "0a3f4f4f-46ad-4562-acd6-f17730a5aef4",
        "customDetails": null,
        "description": "' The query below identifies creation of unusual identity by the Europium actor to mimic Microsoft Exchange Health Manager Service account using Exchange PowerShell commands\n  Reference: https://www.microsoft.com/security/blog/2022/09/08/microsoft-investigates-iranian-attacks-against-the-albanian-government/'\n",
        "displayName": "Unusual identity creation using exchange powershell",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "InitiatingProcessAccount",
                "identifier": "FullName"
              },
              {
                "columnName": "AccountName",
                "identifier": "Name"
              },
              {
                "columnName": "AccountDomain",
                "identifier": "NTDomain"
              }
            ]
          },
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "DeviceName",
                "identifier": "FullName"
              },
              {
                "columnName": "HostName",
                "identifier": "HostName"
              },
              {
                "columnName": "HostNameDomain",
                "identifier": "NTDomain"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Detections/MultipleDataSources/EuropiumUnusualIdentity.yaml",
        "query": "(union isfuzzy=true\n(SecurityEvent\n| where EventID==4688\n| where CommandLine has_any (\"New-Mailbox\",\"Update-RoleGroupMember\") and CommandLine has \"HealthMailbox55x2yq\"\n| project TimeGenerated, DeviceName = Computer, AccountName = SubjectUserName, AccountDomain = SubjectDomainName, ProcessName, ProcessNameFullPath = NewProcessName, EventID, Activity, CommandLine, EventSourceName, Type\n| extend InitiatingProcessAccount = strcat(AccountDomain, \"\\\\\", AccountName)\n),\n(DeviceProcessEvents\n| where ProcessCommandLine has_any (\"New-Mailbox\",\"Update-RoleGroupMember\") and ProcessCommandLine has \"HealthMailbox55x2yq\"\n| extend timestamp = TimeGenerated, AccountDomain = InitiatingProcessAccountDomain, AccountName = InitiatingProcessAccountName\n| extend InitiatingProcessAccount = strcat(AccountDomain, \"\\\\\", AccountName)\n)\n)\n| extend HostName = tostring(split(DeviceName, \".\")[0]), DomainIndex = toint(indexof(DeviceName, '.'))\n| extend HostNameDomain = iff(DomainIndex != -1, substring(DeviceName, DomainIndex + 1), DeviceName)\n",
        "queryFrequency": "PT12H",
        "queryPeriod": "PT12H",
        "severity": "High",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Persistence"
        ],
        "tags": [
          "Europium"
        ],
        "techniques": [
          "T1136"
        ],
        "templateVersion": "1.1.1",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}