Detectionhightest

Suspicious Windows Defender Registry Key Tampering Via Reg.EXE

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

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Launch

Florian Roth (Nextron Systems), Swachchhanda Shrawan Poudel, Nasreddine Bencherchali (Nextron Systems)Created Tue Mar 22Updated Wed Jun 04452bce90-6fb0-43cc-97a5-affc283139b3windows

Log Source

WindowsProcess Creation

ProductWindows← raw: windows

CategoryProcess Creation← raw: process_creation

Events generated when a new process is spawned on the system. Covers command-line arguments, parent/child relationships, and process metadata.

Detection Logic

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_*