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

triggerThreshold: 0
queryPeriod: 1h
kind: Scheduled
queryFrequency: 1h
status: Available
triggerOperator: gt
version: 1.0.0
name: Detect Windows Update Disabled from Registry
id: f1443a87-78d5-40c3-b051-f468f0f2def0
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.
tactics:
- DefenseEvasion
severity: Medium
entityMappings:
- entityType: Host
  fieldMappings:
  - identifier: HostName
    columnName: HostName
  - identifier: DnsDomain
    columnName: DnsDomain
  - identifier: NTDomain
    columnName: NTDomain
- entityType: Account
  fieldMappings:
  - identifier: Name
    columnName: Username
  - identifier: UPNSuffix
    columnName: UPNSuffix
  - identifier: NTDomain
    columnName: NTDomain
- entityType: Process
  fieldMappings:
  - identifier: ProcessId
    columnName: ActingProcessId
  - identifier: CommandLine
    columnName: ActingProcessCommandLine
- entityType: RegistryKey
  fieldMappings:
  - identifier: Hive
    columnName: RegHive
  - identifier: Key
    columnName: RegKey
- entityType: RegistryValue
  fieldMappings:
  - identifier: Name
    columnName: RegistryValue
  - identifier: Value
    columnName: RegistryValueData
  - identifier: ValueType
    columnName: RegistryValueType
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), '\\'))   
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
alertDetailsOverride:
  alertDescriptionFormat: Windows Update Disabled from Registry {{RegKey}} on {{HostName}} by {{Username}}
  alertDisplayNameFormat: Windows Update Disabled from Registry on {{HostName}}
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Malware Protection Essentials/Analytic Rules/WindowsUpdateDisabled.yaml
tags:
- Schema: _ASim_RegistryEvent
  SchemaVersion: 0.1.2
relevantTechniques:
- T1562

ARM