Exchange AuditLog Disabled

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Id	194dd92e-d6e7-4249-85a5-273350a7f5ce
Rulename	Exchange AuditLog Disabled
Description	Identifies when the exchange audit logging has been disabled which may be an adversary attempt to evade detection or avoid other defenses.
Severity	Medium
Tactics	DefenseEvasion
Techniques	T1562
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/exchange_auditlogdisabled.yaml
Version	2.0.5
Arm template	194dd92e-d6e7-4249-85a5-273350a7f5ce.json

KQL

OfficeActivity
| where OfficeWorkload =~ "Exchange" 
| where UserType in~ ("Admin","DcAdmin")
// Only admin or global-admin can disable audit logging
| where Operation =~ "Set-AdminAuditLogConfig"
| extend AdminAuditLogEnabledValue = tostring(parse_json(tostring(parse_json(tostring(array_slice(parse_json(Parameters),3,3)))[0])).Value)
| where AdminAuditLogEnabledValue =~ "False"
| summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), OperationCount = count() by Operation, UserType, UserId, ClientIP, ResultStatus, Parameters, AdminAuditLogEnabledValue
| extend AccountName = iff(UserId contains '@', tostring(split(UserId, '@')[0]), UserId)
| extend AccountUPNSuffix = iff(UserId contains '@', tostring(split(UserId, '@')[1]), '')
| extend AccountName = iff(UserId contains '\\', tostring(split(UserId, '\\')[1]), AccountName)
| extend AccountNTDomain = iff(UserId contains '\\', tostring(split(UserId, '\\')[0]), '')

YAML

name: Exchange AuditLog Disabled
query: |
  OfficeActivity
  | where OfficeWorkload =~ "Exchange" 
  | where UserType in~ ("Admin","DcAdmin")
  // Only admin or global-admin can disable audit logging
  | where Operation =~ "Set-AdminAuditLogConfig"
  | extend AdminAuditLogEnabledValue = tostring(parse_json(tostring(parse_json(tostring(array_slice(parse_json(Parameters),3,3)))[0])).Value)
  | where AdminAuditLogEnabledValue =~ "False"
  | summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), OperationCount = count() by Operation, UserType, UserId, ClientIP, ResultStatus, Parameters, AdminAuditLogEnabledValue
  | extend AccountName = iff(UserId contains '@', tostring(split(UserId, '@')[0]), UserId)
  | extend AccountUPNSuffix = iff(UserId contains '@', tostring(split(UserId, '@')[1]), '')
  | extend AccountName = iff(UserId contains '\\', tostring(split(UserId, '\\')[1]), AccountName)
  | extend AccountNTDomain = iff(UserId contains '\\', tostring(split(UserId, '\\')[0]), '')  
description: |
  'Identifies when the exchange audit logging has been disabled which may be an adversary attempt
  to evade detection or avoid other defenses.'  
tactics:
- DefenseEvasion
requiredDataConnectors:
- dataTypes:
  - OfficeActivity (Exchange)
  connectorId: Office365
queryPeriod: 1d
queryFrequency: 1d
status: Available
triggerThreshold: 0
id: 194dd92e-d6e7-4249-85a5-273350a7f5ce
triggerOperator: gt
version: 2.0.5
relevantTechniques:
- T1562
severity: Medium
kind: Scheduled
entityMappings:
- entityType: Account
  fieldMappings:
  - identifier: FullName
    columnName: UserId
  - identifier: Name
    columnName: AccountName
  - identifier: UPNSuffix
    columnName: AccountUPNSuffix
- entityType: Account
  fieldMappings:
  - identifier: Name
    columnName: AccountNTDomain
- entityType: IP
  fieldMappings:
  - identifier: Address
    columnName: ClientIP
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft 365/Analytic Rules/exchange_auditlogdisabled.yaml

ARM

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2023-02-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/194dd92e-d6e7-4249-85a5-273350a7f5ce')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/194dd92e-d6e7-4249-85a5-273350a7f5ce')]",
      "properties": {
        "alertRuleTemplateName": "194dd92e-d6e7-4249-85a5-273350a7f5ce",
        "customDetails": null,
        "description": "'Identifies when the exchange audit logging has been disabled which may be an adversary attempt\nto evade detection or avoid other defenses.'\n",
        "displayName": "Exchange AuditLog Disabled",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "UserId",
                "identifier": "FullName"
              },
              {
                "columnName": "AccountName",
                "identifier": "Name"
              },
              {
                "columnName": "AccountUPNSuffix",
                "identifier": "UPNSuffix"
              }
            ]
          },
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "AccountNTDomain",
                "identifier": "Name"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "ClientIP",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft 365/Analytic Rules/exchange_auditlogdisabled.yaml",
        "query": "OfficeActivity\n| where OfficeWorkload =~ \"Exchange\" \n| where UserType in~ (\"Admin\",\"DcAdmin\")\n// Only admin or global-admin can disable audit logging\n| where Operation =~ \"Set-AdminAuditLogConfig\"\n| extend AdminAuditLogEnabledValue = tostring(parse_json(tostring(parse_json(tostring(array_slice(parse_json(Parameters),3,3)))[0])).Value)\n| where AdminAuditLogEnabledValue =~ \"False\"\n| summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), OperationCount = count() by Operation, UserType, UserId, ClientIP, ResultStatus, Parameters, AdminAuditLogEnabledValue\n| extend AccountName = iff(UserId contains '@', tostring(split(UserId, '@')[0]), UserId)\n| extend AccountUPNSuffix = iff(UserId contains '@', tostring(split(UserId, '@')[1]), '')\n| extend AccountName = iff(UserId contains '\\\\', tostring(split(UserId, '\\\\')[1]), AccountName)\n| extend AccountNTDomain = iff(UserId contains '\\\\', tostring(split(UserId, '\\\\')[0]), '')\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "severity": "Medium",
        "status": "Available",
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "DefenseEvasion"
        ],
        "techniques": [
          "T1562"
        ],
        "templateVersion": "2.0.5",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}