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	2.0.6
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

version: 2.0.6
tactics:
- DefenseEvasion
relevantTechniques:
- T1562
entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: UserId
  - identifier: Name
    columnName: AccountName
  - identifier: UPNSuffix
    columnName: AccountUPNSuffix
  entityType: Account
- fieldMappings:
  - identifier: Name
    columnName: AccountNTDomain
  entityType: Account
- fieldMappings:
  - identifier: Address
    columnName: ClientIP
  entityType: IP
triggerThreshold: 0
name: Exchange AuditLog Disabled
queryFrequency: 1d
triggerOperator: gt
kind: Scheduled
description: |
    'Identifies when the exchange audit logging has been disabled which may be an adversary attempt to evade detection or avoid other defenses.'
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft 365/Analytic Rules/exchange_auditlogdisabled.yaml
requiredDataConnectors:
- dataTypes:
  - OfficeActivity (Exchange)
  connectorId: Office365
severity: Medium
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]), '')  
queryPeriod: 1d
id: 194dd92e-d6e7-4249-85a5-273350a7f5ce
status: Available

ARM