Detect Windows Update Disabled from Registry

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Id	f1443a87-78d5-40c3-b051-f468f0f2def0
Rulename	Detect Windows Update Disabled from Registry
Description	This analytic rule detects any registry value creation or modification of Windows Update registry keys to disable Windows Update. This could be an indication of defense evasion by an adversary on a compromised host.
Severity	Medium
Tactics	DefenseEvasion
Techniques	T1562
Required data connectors	CiscoSecureEndpoint CrowdStrikeFalconEndpointProtection MicrosoftThreatProtection SentinelOne TrendMicroApexOne TrendMicroApexOneAma VMwareCarbonBlack
Kind	Scheduled
Query frequency	1h
Query period	1h
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Malware Protection Essentials/Analytic Rules/WindowsUpdateDisabled.yaml
Version	1.0.0
Arm template	f1443a87-78d5-40c3-b051-f468f0f2def0.json

KQL

// List of Windows Firewall registry keys to monitor
let windowsUpdateRegistryList = dynamic([
  'HKEY_LOCAL_MACHINE\\Software\\Policies\\Microsoft\\Windows\\WindowsUpdate',
  'HKEY_LOCAL_MACHINE\\Software\\Policies\\Microsoft\\Windows\\WindowsUpdate\\AU'
  ]);
_ASim_RegistryEvent
| where EventType in ('RegistryValueSet', 'RegistryKeyCreated') 
| where RegistryKey has_any (windowsUpdateRegistryList) 
| where RegistryValue has_any ('AUOptions', 'NoAutoUpdate') and RegistryValueData == '1'
| project
    TimeGenerated,
    DvcHostname,
    ActorUsername,
    ActorUsernameType,
    ActingProcessId,
    ActingProcessName,
    ActingProcessCommandLine,
    RegistryKey,
    RegistryValue,
    RegistryValueType,
    RegistryValueData
| extend HostName = tostring(split(DvcHostname, '.')[0])
| extend DnsDomain = tostring(strcat_array(array_slice(split(DvcHostname, '.'), 1, -1), '.'))
| extend Username = iff(tostring(ActorUsernameType) == 'Windows', tostring(split(ActorUsername, '\\')[1]), ActorUsername)
| extend NTDomain = iff(tostring(ActorUsernameType) == 'Windows', tostring(split(ActorUsername, '\\')[0]), ActorUsername)
| extend Username = iff(tostring(ActorUsernameType) == 'UPN', tostring(split(ActorUsername, '@')[0]), Username)
| extend UPNSuffix = iff(tostring(ActorUsernameType) == 'UPN', tostring(split(ActorUsername, '@')[1]), '')
| extend RegHive = tostring(split(RegistryKey, '\\')[0]), RegKey = tostring(strcat_array(array_slice(split(RegistryKey, '\\'), 1, -1), '\\'))

YAML

name: Detect Windows Update Disabled from Registry
relevantTechniques:
- T1562
id: f1443a87-78d5-40c3-b051-f468f0f2def0
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Malware Protection Essentials/Analytic Rules/WindowsUpdateDisabled.yaml
requiredDataConnectors:
- dataTypes:
  - CommonSecurityLog
  connectorId: CrowdStrikeFalconEndpointProtection
- dataTypes:
  - SecurityAlert
  connectorId: MicrosoftThreatProtection
- dataTypes:
  - SentinelOne_CL
  connectorId: SentinelOne
- dataTypes:
  - CarbonBlackEvents_CL
  connectorId: VMwareCarbonBlack
- dataTypes:
  - CiscoSecureEndpoint_CL
  connectorId: CiscoSecureEndpoint
- dataTypes:
  - TMApexOneEvent
  connectorId: TrendMicroApexOne
- dataTypes:
  - TMApexOneEvent
  connectorId: TrendMicroApexOneAma
eventGroupingSettings:
  aggregationKind: singleAlert
version: 1.0.0
severity: Medium
triggerThreshold: 0
tags:
- SchemaVersion: 0.1.2
  Schema: _ASim_RegistryEvent
queryPeriod: 1h
entityMappings:
- fieldMappings:
  - identifier: HostName
    columnName: HostName
  - identifier: DnsDomain
    columnName: DnsDomain
  - identifier: NTDomain
    columnName: NTDomain
  entityType: Host
- fieldMappings:
  - identifier: Name
    columnName: Username
  - identifier: UPNSuffix
    columnName: UPNSuffix
  - identifier: NTDomain
    columnName: NTDomain
  entityType: Account
- fieldMappings:
  - identifier: ProcessId
    columnName: ActingProcessId
  - identifier: CommandLine
    columnName: ActingProcessCommandLine
  entityType: Process
- fieldMappings:
  - identifier: Hive
    columnName: RegHive
  - identifier: Key
    columnName: RegKey
  entityType: RegistryKey
- fieldMappings:
  - identifier: Name
    columnName: RegistryValue
  - identifier: Value
    columnName: RegistryValueData
  - identifier: ValueType
    columnName: RegistryValueType
  entityType: RegistryValue
alertDetailsOverride:
  alertDisplayNameFormat: Windows Update Disabled from Registry on {{HostName}}
  alertDescriptionFormat: Windows Update Disabled from Registry {{RegKey}} on {{HostName}} by {{Username}}
queryFrequency: 1h
status: Available
query: |
  // List of Windows Firewall registry keys to monitor
  let windowsUpdateRegistryList = dynamic([
    'HKEY_LOCAL_MACHINE\\Software\\Policies\\Microsoft\\Windows\\WindowsUpdate',
    'HKEY_LOCAL_MACHINE\\Software\\Policies\\Microsoft\\Windows\\WindowsUpdate\\AU'
    ]);
  _ASim_RegistryEvent
  | where EventType in ('RegistryValueSet', 'RegistryKeyCreated') 
  | where RegistryKey has_any (windowsUpdateRegistryList) 
  | where RegistryValue has_any ('AUOptions', 'NoAutoUpdate') and RegistryValueData == '1'
  | project
      TimeGenerated,
      DvcHostname,
      ActorUsername,
      ActorUsernameType,
      ActingProcessId,
      ActingProcessName,
      ActingProcessCommandLine,
      RegistryKey,
      RegistryValue,
      RegistryValueType,
      RegistryValueData
  | extend HostName = tostring(split(DvcHostname, '.')[0])
  | extend DnsDomain = tostring(strcat_array(array_slice(split(DvcHostname, '.'), 1, -1), '.'))
  | extend Username = iff(tostring(ActorUsernameType) == 'Windows', tostring(split(ActorUsername, '\\')[1]), ActorUsername)
  | extend NTDomain = iff(tostring(ActorUsernameType) == 'Windows', tostring(split(ActorUsername, '\\')[0]), ActorUsername)
  | extend Username = iff(tostring(ActorUsernameType) == 'UPN', tostring(split(ActorUsername, '@')[0]), Username)
  | extend UPNSuffix = iff(tostring(ActorUsernameType) == 'UPN', tostring(split(ActorUsername, '@')[1]), '')
  | extend RegHive = tostring(split(RegistryKey, '\\')[0]), RegKey = tostring(strcat_array(array_slice(split(RegistryKey, '\\'), 1, -1), '\\'))   
tactics:
- DefenseEvasion
kind: Scheduled
description: |
    This analytic rule detects any registry value creation or modification of Windows Update registry keys to disable Windows Update. This could be an indication of defense evasion by an adversary on a compromised host.
triggerOperator: gt

ARM