Detection rules › YARA-L

Disable Internal Tools or Feature in Registry

Severity
medium
Type
Detection
Time window
5m
Match by
hostname
Source
github.com/chronicle/detection-rules

Detects registry modifications that change features of internal Windows tools (malware like Agent Tesla uses this technique)

MITRE ATT&CK coverage

TacticTechniques
PersistenceT1112 Modify Registry
Defense ImpairmentT1112 Modify Registry

References

Event coverage

Rule body yaral

/*
 * Copyright 2025 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

rule disable_internal_tools_or_feature_in_registry {

  meta:
    author = "frack113, Nasreddine Bencherchali (Nextron Systems), CrimpSec"
    description = "Detects registry modifications that change features of internal Windows tools (malware like Agent Tesla uses this technique)"
    reference = "https://github.com/SigmaHQ/sigma/blob/master/rules/windows/registry/registry_set/registry_set_disable_function_user.yml"
    license = "https://github.com/SigmaHQ/Detection-Rule-License/blob/main/LICENSE.Detection.Rules.md"
    rule_name = "Disable Internal Tools or Feature in Registry"
    rule_id = "mr_5840c962-0e51-47e6-9941-d143ebaae00d"
    sigma_uuid = "e2482f8d-3443-4237-b906-cc145d87a076"
    sigma_status = "test"
    tactic = "TA0005"
    technique = "T1112"
    type = "Detection"
    data_source = "Windows Registry"
    platform = "Windows"
    severity = "Medium"
    priority = "Medium"
    false_positives = "Legitimate admin script"

  events:
    $reg.metadata.event_type = "REGISTRY_MODIFICATION"
    (
        (
            (
                re.regex($reg.target.registry.registry_key, `SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\Explorer\\DisableCMD$`) nocase or
                re.regex($reg.target.registry.registry_key, `SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\Explorer\\NoControlPanel$`) nocase or
                re.regex($reg.target.registry.registry_key, `SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\Explorer\\NoRun$`) nocase or
                re.regex($reg.target.registry.registry_key, `SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\Explorer\\StartMenuLogOff$`) nocase or
                re.regex($reg.target.registry.registry_key, `SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\DisableChangePassword$`) nocase or
                re.regex($reg.target.registry.registry_key, `SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\DisableLockWorkstation$`) nocase or
                re.regex($reg.target.registry.registry_key, `SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\DisableRegistryTools$`) nocase or
                re.regex($reg.target.registry.registry_key, `SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\DisableTaskmgr$`) nocase or
                re.regex($reg.target.registry.registry_key, `SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\NoDispBackgroundPage$`) nocase or
                re.regex($reg.target.registry.registry_key, `SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\NoDispCPL$`) nocase or
                re.regex($reg.target.registry.registry_key, `SOFTWARE\\Policies\\Microsoft\\Windows\\Explorer\\DisableNotificationCenter$`) nocase or
                re.regex($reg.target.registry.registry_key, `SOFTWARE\\Policies\\Microsoft\\Windows\\System\\DisableCMD$`) nocase
            ) and
            $reg.target.registry.registry_value_data = "DWORD (0x00000001)" nocase
        )
        or
        (
            (
                re.regex($reg.target.registry.registry_key, `SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\ConsentPromptBehaviorAdmin$`) nocase or
                re.regex($reg.target.registry.registry_key, `Software\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\InactivityTimeoutSecs$`) nocase or
                re.regex($reg.target.registry.registry_key, `SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\shutdownwithoutlogon$`) nocase or
                re.regex($reg.target.registry.registry_key, `SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\PushNotifications\\ToastEnabled$`) nocase or
                re.regex($reg.target.registry.registry_key, `SYSTEM\\CurrentControlSet\\Control\\Storage\\Write Protection$`) nocase or
                re.regex($reg.target.registry.registry_key, `SYSTEM\\CurrentControlSet\\Control\\StorageDevicePolicies\\WriteProtect$`) nocase
            ) and
            $reg.target.registry.registry_value_data = "DWORD (0x00000000)" nocase
        )
    )
    $reg.principal.hostname = $hostname

  match:
    $hostname over 5m

  outcome:
    //example usage of specifying test user and hostname to adjust risk score
    $risk_score = max(if($reg.principal.user.userid = "user" and $reg.principal.hostname = "hostname", 0, 15))
    $principal_hostname = array_distinct($reg.principal.hostname)
    $principal_process_pid = array_distinct($reg.principal.process.pid)
    $principal_process_file_full_path = array_distinct($reg.principal.process.file.full_path)
    $principal_process_product_specific_process_id = array_distinct($reg.principal.process.product_specific_process_id)
    $principal_user_userid = array_distinct($reg.principal.user.userid)
    $target_registry_key = array_distinct($reg.target.registry.registry_key)
    $target_registry_value_data = array_distinct($reg.target.registry.registry_value_data)
    $log_type = array_distinct(strings.concat($reg.metadata.log_type,"/",$reg.metadata.product_event_type))

  condition:
    $reg
}

Stages and Predicates

Stage 0: match + condition

match:
    $hostname over 5m
condition:
    $reg

Fires when at least one $reg event in the 5m window.

Stage 1: events: $reg · REGISTRY_MODIFICATION

$reg.metadata.event_type = "REGISTRY_MODIFICATION"
(
    (
        (
            re.regex($reg.target.registry.registry_key, `SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\Explorer\\DisableCMD$`) nocase or
            re.regex($reg.target.registry.registry_key, `SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\Explorer\\NoControlPanel$`) nocase or
            re.regex($reg.target.registry.registry_key, `SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\Explorer\\NoRun$`) nocase or
            re.regex($reg.target.registry.registry_key, `SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\Explorer\\StartMenuLogOff$`) nocase or
            re.regex($reg.target.registry.registry_key, `SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\DisableChangePassword$`) nocase or
            re.regex($reg.target.registry.registry_key, `SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\DisableLockWorkstation$`) nocase or
            re.regex($reg.target.registry.registry_key, `SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\DisableRegistryTools$`) nocase or
            re.regex($reg.target.registry.registry_key, `SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\DisableTaskmgr$`) nocase or
            re.regex($reg.target.registry.registry_key, `SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\NoDispBackgroundPage$`) nocase or
            re.regex($reg.target.registry.registry_key, `SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\NoDispCPL$`) nocase or
            re.regex($reg.target.registry.registry_key, `SOFTWARE\\Policies\\Microsoft\\Windows\\Explorer\\DisableNotificationCenter$`) nocase or
            re.regex($reg.target.registry.registry_key, `SOFTWARE\\Policies\\Microsoft\\Windows\\System\\DisableCMD$`) nocase
        ) and
        $reg.target.registry.registry_value_data = "DWORD (0x00000001)" nocase
    )
    or
    (
        (
            re.regex($reg.target.registry.registry_key, `SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\ConsentPromptBehaviorAdmin$`) nocase or
            re.regex($reg.target.registry.registry_key, `Software\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\InactivityTimeoutSecs$`) nocase or
            re.regex($reg.target.registry.registry_key, `SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\shutdownwithoutlogon$`) nocase or
            re.regex($reg.target.registry.registry_key, `SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\PushNotifications\\ToastEnabled$`) nocase or
            re.regex($reg.target.registry.registry_key, `SYSTEM\\CurrentControlSet\\Control\\Storage\\Write Protection$`) nocase or
            re.regex($reg.target.registry.registry_key, `SYSTEM\\CurrentControlSet\\Control\\StorageDevicePolicies\\WriteProtect$`) nocase
        ) and
        $reg.target.registry.registry_value_data = "DWORD (0x00000000)" nocase
    )
)
$reg.principal.hostname = $hostname

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
target.registry.registry_keyregex_match
  • SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer\DisableCMD$ transforms: nocase
  • SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer\NoControlPanel$ transforms: nocase
  • SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer\NoRun$ transforms: nocase
  • SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer\StartMenuLogOff$ transforms: nocase
  • SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\ConsentPromptBehaviorAdmin$ transforms: nocase
  • SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\DisableChangePassword$ transforms: nocase
  • SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\DisableLockWorkstation$ transforms: nocase
  • SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\DisableRegistryTools$ transforms: nocase
  • SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\DisableTaskmgr$ transforms: nocase
  • SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\NoDispBackgroundPage$ transforms: nocase
  • SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\NoDispCPL$ transforms: nocase
  • SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\shutdownwithoutlogon$ transforms: nocase
  • SOFTWARE\Microsoft\Windows\CurrentVersion\PushNotifications\ToastEnabled$ transforms: nocase
  • SOFTWARE\Policies\Microsoft\Windows\Explorer\DisableNotificationCenter$ transforms: nocase
  • SOFTWARE\Policies\Microsoft\Windows\System\DisableCMD$ transforms: nocase
  • SYSTEM\CurrentControlSet\Control\StorageDevicePolicies\WriteProtect$ transforms: nocase
  • SYSTEM\CurrentControlSet\Control\Storage\Write Protection$ transforms: nocase
  • Software\Microsoft\Windows\CurrentVersion\Policies\System\InactivityTimeoutSecs$ transforms: nocase
target.registry.registry_value_dataeq
  • DWORD (0x00000000) transforms: nocase corpus 40 (sigma 38, chronicle 2)
  • DWORD (0x00000001) transforms: nocase corpus 42 (sigma 38, chronicle 4)

Output fields

Fields the rule emits when it matches. Chronicle authors list these in the outcome block; they appear on the detection and $risk_score drives alerting. Sentinel / Defender XDR rules build them up through project / summarize / extend stages. Sentinel maps these into alert fields via entityMappings and customDetails; Defender XDR custom detections surface them as alert fields directly.

FieldSource
risk_scoremax(if($reg.principal.user.userid = "user" and $reg.principal.hostname = "hostname", 0, 15))
principal_hostnamearray_distinct($reg.principal.hostname)
principal_process_pidarray_distinct($reg.principal.process.pid)
principal_process_file_full_patharray_distinct($reg.principal.process.file.full_path)
principal_process_product_specific_process_idarray_distinct($reg.principal.process.product_specific_process_id)
principal_user_useridarray_distinct($reg.principal.user.userid)
target_registry_keyarray_distinct($reg.target.registry.registry_key)
target_registry_value_dataarray_distinct($reg.target.registry.registry_value_data)
log_typearray_distinct(strings.concat($reg.metadata.log_type,"/",$reg.metadata.product_event_type))