Suspicious Windows Defender Registry Key Tampering Via Reg.EXE

Status: test
Severity: high
Log source: product windows, category process_creation
Author: Florian Roth (Nextron Systems), Swachchhanda Shrawan Poudel, Nasreddine Bencherchali (Nextron Systems)
Source: github.com/SigmaHQ/sigma

Detects the usage of "reg.exe" to tamper with different Windows Defender registry keys in order to disable some important features related to protection and detection

MITRE ATT&CK coverage

Tactic	Techniques
Defense Impairment	`T1685` Disable or Modify Tools

Event coverage

Provider	Event	Title
Sysmon	Event ID 1	Process creation

Rule body yaml

title: Suspicious Windows Defender Registry Key Tampering Via Reg.EXE
id: 452bce90-6fb0-43cc-97a5-affc283139b3
status: test
description: |
    Detects the usage of "reg.exe" to tamper with different Windows Defender registry keys in order to disable some important features related to protection and detection
references:
    - https://thedfirreport.com/2022/03/21/apt35-automates-initial-access-using-proxyshell/
    - https://github.com/swagkarna/Defeat-Defender-V1.2.0/tree/ae4059c4276da6f6303b8f53cdff085ecae88a91
    - https://www.elevenforum.com/t/video-guide-how-to-completely-disable-microsoft-defender-antivirus.14608/page-2
    - https://tria.ge/241231-j9yatstqbm/behavioral1
author: Florian Roth (Nextron Systems), Swachchhanda Shrawan Poudel, Nasreddine Bencherchali (Nextron Systems)
date: 2022-03-22
modified: 2025-06-04
tags:
    - attack.defense-impairment
    - attack.t1685
logsource:
    category: process_creation
    product: windows
detection:
    selection_root_img:
        - Image|endswith: '\reg.exe'
        - OriginalFileName: 'reg.exe'
    selection_root_path:
        CommandLine|contains:
            - 'SOFTWARE\Microsoft\Windows Defender\'
            - 'SOFTWARE\Policies\Microsoft\Windows Defender Security Center'
            - 'SOFTWARE\Policies\Microsoft\Windows Defender\'
    selection_dword_0:
        CommandLine|contains|all:
            - ' add '
            - 'd 0'
        CommandLine|contains:
            - 'DisallowExploitProtectionOverride'
            - 'EnableControlledFolderAccess'
            - 'MpEnablePus'
            - 'PUAProtection'
            - 'SpynetReporting'
            - 'SubmitSamplesConsent'
            - 'TamperProtection'
    selection_dword_1:
        CommandLine|contains|all:
            - ' add '
            - 'd 1'
        CommandLine|contains:
            - 'DisableAccess'
            - 'DisableAntiSpyware'
            - 'DisableAntiSpywareRealtimeProtection'
            - 'DisableAntiVirus'
            - 'DisableAntiVirusSignatures'
            - 'DisableArchiveScanning'
            - 'DisableBehaviorMonitoring'
            - 'DisableBlockAtFirstSeen'
            - 'DisableCloudProtection'
            - 'DisableConfig'
            - 'DisableEnhancedNotifications'
            - 'DisableIntrusionPreventionSystem'
            - 'DisableIOAVProtection'
            - 'DisableNetworkProtection'
            - 'DisableOnAccessProtection'
            - 'DisablePrivacyMode'
            - 'DisableRealtimeMonitoring'
            - 'DisableRoutinelyTakingAction'
            - 'DisableScanOnRealtimeEnable'
            - 'DisableScriptScanning'
            - 'DisableSecurityCenter'
            - 'Notification_Suppress'
            - 'SignatureDisableUpdateOnStartupWithoutEngine'
    condition: all of selection_root_* and 1 of selection_dword_*
falsepositives:
    - Rare legitimate use by administrators to test software (should always be investigated)
level: high

Stages and Predicates

Stage 0: `condition`

all of selection_root_* and 1 of selection_dword_*

Stage 1: `selection_root_img`

selection_root_img:
    - Image|endswith: '\reg.exe'
    - OriginalFileName: 'reg.exe'

Stage 2: `selection_root_path`

selection_root_path:
    CommandLine|contains:
        - 'SOFTWARE\Microsoft\Windows Defender\'
        - 'SOFTWARE\Policies\Microsoft\Windows Defender Security Center'
        - 'SOFTWARE\Policies\Microsoft\Windows Defender\'

Stage 3: `selection_dword_0`

selection_dword_0:
    CommandLine|contains|all:
        - ' add '
        - 'd 0'
    CommandLine|contains:
        - 'DisallowExploitProtectionOverride'
        - 'EnableControlledFolderAccess'
        - 'MpEnablePus'
        - 'PUAProtection'
        - 'SpynetReporting'
        - 'SubmitSamplesConsent'
        - 'TamperProtection'

Stage 4: `selection_dword_1`

selection_dword_1:
    CommandLine|contains|all:
        - ' add '
        - 'd 1'
    CommandLine|contains:
        - 'DisableAccess'
        - 'DisableAntiSpyware'
        - 'DisableAntiSpywareRealtimeProtection'
        - 'DisableAntiVirus'
        - 'DisableAntiVirusSignatures'
        - 'DisableArchiveScanning'
        - 'DisableBehaviorMonitoring'
        - 'DisableBlockAtFirstSeen'
        - 'DisableCloudProtection'
        - 'DisableConfig'
        - 'DisableEnhancedNotifications'
        - 'DisableIntrusionPreventionSystem'
        - 'DisableIOAVProtection'
        - 'DisableNetworkProtection'
        - 'DisableOnAccessProtection'
        - 'DisablePrivacyMode'
        - 'DisableRealtimeMonitoring'
        - 'DisableRoutinelyTakingAction'
        - 'DisableScanOnRealtimeEnable'
        - 'DisableScriptScanning'
        - 'DisableSecurityCenter'
        - 'Notification_Suppress'
        - 'SignatureDisableUpdateOnStartupWithoutEngine'

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.

Field	Kind	Values
`CommandLine`	match	`add` corpus 14 (sigma 12, splunk 1, chronicle 1) `DisableAccess` `DisableAntiSpyware` corpus 3 (sigma 3) `DisableAntiSpywareRealtimeProtection` `DisableAntiVirus` `DisableAntiVirusSignatures` `DisableArchiveScanning` corpus 2 (sigma 2) `DisableBehaviorMonitoring` corpus 2 (sigma 2) `DisableBlockAtFirstSeen` corpus 2 (sigma 2) `DisableCloudProtection` `DisableConfig` corpus 2 (sigma 2) `DisableEnhancedNotifications` `DisableIOAVProtection` corpus 2 (sigma 2) `DisableIntrusionPreventionSystem` corpus 2 (sigma 2) `DisableNetworkProtection` `DisableOnAccessProtection` `DisablePrivacyMode` `DisableRealtimeMonitoring` corpus 3 (sigma 2, kusto 1) `DisableRoutinelyTakingAction` `DisableScanOnRealtimeEnable` `DisableScriptScanning` corpus 2 (sigma 2) `DisableSecurityCenter` `DisallowExploitProtectionOverride` `EnableControlledFolderAccess` `MpEnablePus` `Notification_Suppress` `PUAProtection` corpus 2 (sigma 1, splunk 1) `SOFTWARE\Microsoft\Windows Defender\` `SOFTWARE\Policies\Microsoft\Windows Defender Security Center` `SOFTWARE\Policies\Microsoft\Windows Defender\` `SignatureDisableUpdateOnStartupWithoutEngine` corpus 2 (sigma 2) `SpynetReporting` `SubmitSamplesConsent` `TamperProtection` `d 0` `d 1`
`Image`	ends_with	`\reg.exe` corpus 58 (sigma 58)
`OriginalFileName`	eq	`reg.exe` corpus 42 (sigma 32, splunk 8, elastic 2)

`j` / `k`	Scroll down / up
`d` / `u`	Half-page down / up
`gg` / `G`	Top / bottom
`h` / `l`	History back / forward
`f`	Follow link (`Shift` = new tab)
`/`	Focus search
`?`	Toggle this help
`↑` / `↓`	Navigate search results
`Enter`	Open highlighted result
`Esc`	Close results / dialog

`type:`	`events` / `rules` / `providers`
`vendor:`	`sigma` / `elastic` / `splunk` / `kusto` / `chronicle` (vendor name alone also works: `sigma:`, `kql:`, `secops:`…)
`tactic:`	TA-id, slug, or name: `credential_access`, `TA0006`
`technique:`	technique or sub-technique ID: `T1003`, `T1003.001` (alias `tech:`)
`severity:`	`critical` / `high` / `medium` / `low` / `informational` (alias `sev:`)
`risk_score`	Numeric comparison on the Elastic risk score (0 to 100): `risk_score>50`, `risk_score<=20`, `risk_score=99` (alias `risk`; Elastic rules only)
`stages:`	Rules with exactly N pipeline stages
`correlation:`	`single_event` / `sequence` / `alternatives` / `alternatives_cross_log` / `all_required` / `correlated`
`with:`	Co-occurrence event-id; stacks (`with:4624 with:4769`) to require all, while a comma list in one occurrence (`with:4624,4769`) is an either-or group. Implies multi-event
`like:`	Structural neighbors of a rule slug (equivalents + subsumption stricter / broader): `like:comsvcs_lsass_memory_dump-splunk-sysmon`
`groupby:`	Entity-grouping substring match against `group_by_keys`: `groupby:user`, `groupby:host`
`uses:`	Rules whose predicate tree touches the field (any kind, any value): `uses:CommandLine`
`excludes:`	Rules with top-level `not()` clauses on the field (FP whitelists): `excludes:ParentImage`
`field:` / `value:`	Predicate search; narrows rule cards to those with a matching leaf and drives the indicator tier. Unquoted = substring, wildcards allowed (`value:mimikatz`)
`indicator:`	Shorthand for `field:F value:V`: `indicator:Image=*\powershell.exe`
`kind:`	Filter by predicate kind. Narrows rule cards to those carrying a matching predicate leaf (`vendor:elastic kind:cidr_match`) and drives the indicator tier: `contains` / `starts_with` / `ends_with` / `regex` / `cidr` / `eq` / `in` … (operator aliases `op:`/`match:`)
`has:` / `no:`	`sample`, `field`, `notes`, `refs`, `trace`, `thirdparty`, `rule`, `pattern`, `timewindow`, `threshold`, `newterms`, `sigma`/`elastic`/`splunk`/`kusto`/`chronicle`
`-op:val`	Exclude matches; works on most operators but not `type:`/`like:`/`has:`/`no:` (use `no:<flag>` to exclude a rule flag): `tactic:execution -vendor:splunk`. Standalone `-kind:`/`-field:`/`-value:` drop every rule carrying a matching predicate leaf (`type:rules -kind:is_null`)
`field:"…"` / `value:"…"`	Quoted value = anchored exact match (also allows spaces): `value:"net user"`
`a,b`	Comma = OR inside one operator (`vendor:sigma,elastic`, `severity:high,critical`); repeating a facet merges the same way. `field:`/`value:` never split (literal commas)
`vendors:` / `stage:`	Singular and plural spellings fold to the canonical operator and value: `tactics:` = `tactic:`, `type:event` = `type:events`, `correlation:sequences` = `correlation:sequence`, `has:thresholds` = `has:threshold`
`"quoted phrase"`	Exact-match a multi-word phrase (free text)

Suspicious Windows Defender Registry Key Tampering Via Reg.EXE

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: `condition`

Stage 1: `selection_root_img`

Stage 2: `selection_root_path`

Stage 3: `selection_dword_0`

Stage 4: `selection_dword_1`

Indicators

Keyboard shortcuts

Search operators

Suspicious Windows Defender Registry Key Tampering Via Reg.EXE

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: condition

Stage 1: selection_root_img

Stage 2: selection_root_path

Stage 3: selection_dword_0

Stage 4: selection_dword_1

Indicators

Stage 0: `condition`

Stage 1: `selection_root_img`

Stage 2: `selection_root_path`

Stage 3: `selection_dword_0`

Stage 4: `selection_dword_1`