Rare and potentially high-risk Office operations

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Id	957cb240-f45d-4491-9ba5-93430a3c08be
Rulename	Rare and potentially high-risk Office operations
Description	Identifies Office operations that are typically rare and can provide capabilities useful to attackers.
Severity	Low
Tactics	Persistence Collection
Techniques	T1098 T1114
Required data connectors	Office365
Kind	Scheduled
Query frequency	1d
Query period	1d
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft 365/Analytic Rules/RareOfficeOperations.yaml
Version	2.0.1
Arm template	957cb240-f45d-4491-9ba5-93430a3c08be.json

KQL

OfficeActivity
| where Operation in~ ( "Add-MailboxPermission", "Add-MailboxFolderPermission", "Set-Mailbox", "New-ManagementRoleAssignment", "New-InboxRule", "Set-InboxRule", "Set-TransportRule")
and not(UserId has_any ('NT AUTHORITY\\SYSTEM (Microsoft.Exchange.ServiceHost)', 'NT AUTHORITY\\SYSTEM (w3wp)', 'devilfish-applicationaccount') and Operation in~ ( "Add-MailboxPermission", "Set-Mailbox"))
| extend ClientIPOnly = tostring(extract_all(@'\[?(::ffff:)?(?P<IPAddress>(\d+\.\d+\.\d+\.\d+)|[^\]]+)\]?', dynamic(["IPAddress"]), ClientIP)[0][0])
| extend timestamp = TimeGenerated, AccountCustomEntity = UserId, IPCustomEntity = ClientIPOnly

YAML

severity: Low
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft 365/Analytic Rules/RareOfficeOperations.yaml
description: |
    'Identifies Office operations that are typically rare and can provide capabilities useful to attackers.'
triggerOperator: gt
queryPeriod: 1d
requiredDataConnectors:
- dataTypes:
  - OfficeActivity
  connectorId: Office365
queryFrequency: 1d
triggerThreshold: 0
tactics:
- Persistence
- Collection
query: |
  OfficeActivity
  | where Operation in~ ( "Add-MailboxPermission", "Add-MailboxFolderPermission", "Set-Mailbox", "New-ManagementRoleAssignment", "New-InboxRule", "Set-InboxRule", "Set-TransportRule")
  and not(UserId has_any ('NT AUTHORITY\\SYSTEM (Microsoft.Exchange.ServiceHost)', 'NT AUTHORITY\\SYSTEM (w3wp)', 'devilfish-applicationaccount') and Operation in~ ( "Add-MailboxPermission", "Set-Mailbox"))
  | extend ClientIPOnly = tostring(extract_all(@'\[?(::ffff:)?(?P<IPAddress>(\d+\.\d+\.\d+\.\d+)|[^\]]+)\]?', dynamic(["IPAddress"]), ClientIP)[0][0])
  | extend timestamp = TimeGenerated, AccountCustomEntity = UserId, IPCustomEntity = ClientIPOnly  
status: Available
kind: Scheduled
relevantTechniques:
- T1098
- T1114
version: 2.0.1
id: 957cb240-f45d-4491-9ba5-93430a3c08be
entityMappings:
- fieldMappings:
  - columnName: AccountCustomEntity
    identifier: FullName
  entityType: Account
- fieldMappings:
  - columnName: IPCustomEntity
    identifier: Address
  entityType: IP
name: Rare and potentially high-risk Office operations

ARM

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/957cb240-f45d-4491-9ba5-93430a3c08be')]",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/957cb240-f45d-4491-9ba5-93430a3c08be')]",
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules",
      "kind": "Scheduled",
      "apiVersion": "2022-11-01-preview",
      "properties": {
        "displayName": "Rare and potentially high-risk Office operations",
        "description": "'Identifies Office operations that are typically rare and can provide capabilities useful to attackers.'\n",
        "severity": "Low",
        "enabled": true,
        "query": "OfficeActivity\n| where Operation in~ ( \"Add-MailboxPermission\", \"Add-MailboxFolderPermission\", \"Set-Mailbox\", \"New-ManagementRoleAssignment\", \"New-InboxRule\", \"Set-InboxRule\", \"Set-TransportRule\")\nand not(UserId has_any ('NT AUTHORITY\\\\SYSTEM (Microsoft.Exchange.ServiceHost)', 'NT AUTHORITY\\\\SYSTEM (w3wp)', 'devilfish-applicationaccount') and Operation in~ ( \"Add-MailboxPermission\", \"Set-Mailbox\"))\n| extend ClientIPOnly = tostring(extract_all(@'\\[?(::ffff:)?(?P<IPAddress>(\\d+\\.\\d+\\.\\d+\\.\\d+)|[^\\]]+)\\]?', dynamic([\"IPAddress\"]), ClientIP)[0][0])\n| extend timestamp = TimeGenerated, AccountCustomEntity = UserId, IPCustomEntity = ClientIPOnly\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0,
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Persistence",
          "Collection"
        ],
        "techniques": [
          "T1098",
          "T1114"
        ],
        "alertRuleTemplateName": "957cb240-f45d-4491-9ba5-93430a3c08be",
        "customDetails": null,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "AccountCustomEntity",
                "identifier": "FullName"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "IPCustomEntity",
                "identifier": "Address"
              }
            ]
          }
        ],
        "status": "Available",
        "templateVersion": "2.0.1",
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft 365/Analytic Rules/RareOfficeOperations.yaml"
      }
    }
  ]
}