Tamper Windows Defender - ScriptBlockLogging

 1title: Tamper Windows Defender - ScriptBlockLogging
 2id: 14c71865-6cd3-44ae-adaa-1db923fae5f2
 3related:
 4    - id: ec19ebab-72dc-40e1-9728-4c0b805d722c
 5      type: derived
 6status: experimental
 7description: Detects PowerShell scripts attempting to disable scheduled scanning and other parts of Windows Defender ATP or set default actions to allow.
 8references:
 9    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1562.001/T1562.001.md
10    - https://docs.microsoft.com/en-us/powershell/module/defender/set-mppreference?view=windowsserver2022-ps
11    - https://bidouillesecurity.com/disable-windows-defender-in-powershell/
12author: frack113, elhoim, Tim Shelton (fps, alias support), Swachchhanda Shrawan Poudel, Nasreddine Bencherchali (Nextron Systems)
13date: 2022/01/16
14modified: 2024/01/02
15tags:
16    - attack.defense_evasion
17    - attack.t1562.001
18logsource:
19    product: windows
20    category: ps_script
21    definition: 'Requirements: Script Block Logging must be enabled'
22detection:
23    selection_options_disabling_preference:
24        ScriptBlockText|contains: 'Set-MpPreference'
25    selection_options_disabling_function:
26        ScriptBlockText|contains:
27            - '-dbaf $true'
28            - '-dbaf 1'
29            - '-dbm $true'
30            - '-dbm 1'
31            - '-dips $true'
32            - '-dips 1'
33            - '-DisableArchiveScanning $true'
34            - '-DisableArchiveScanning 1'
35            - '-DisableBehaviorMonitoring $true'
36            - '-DisableBehaviorMonitoring 1'
37            - '-DisableBlockAtFirstSeen $true'
38            - '-DisableBlockAtFirstSeen 1'
39            - '-DisableCatchupFullScan $true'
40            - '-DisableCatchupFullScan 1'
41            - '-DisableCatchupQuickScan $true'
42            - '-DisableCatchupQuickScan 1'
43            - '-DisableIntrusionPreventionSystem $true'
44            - '-DisableIntrusionPreventionSystem 1'
45            - '-DisableIOAVProtection $true'
46            - '-DisableIOAVProtection 1'
47            - '-DisableRealtimeMonitoring $true'
48            - '-DisableRealtimeMonitoring 1'
49            - '-DisableRemovableDriveScanning $true'
50            - '-DisableRemovableDriveScanning 1'
51            - '-DisableScanningMappedNetworkDrivesForFullScan $true'
52            - '-DisableScanningMappedNetworkDrivesForFullScan 1'
53            - '-DisableScanningNetworkFiles $true'
54            - '-DisableScanningNetworkFiles 1'
55            - '-DisableScriptScanning $true'
56            - '-DisableScriptScanning 1'
57            - '-MAPSReporting $false'
58            - '-MAPSReporting 0'
59            - '-drdsc $true'
60            - '-drdsc 1'
61            - '-drtm $true'
62            - '-drtm 1'
63            - '-dscrptsc $true'
64            - '-dscrptsc 1'
65            - '-dsmndf $true'
66            - '-dsmndf 1'
67            - '-dsnf $true'
68            - '-dsnf 1'
69            - '-dss $true'
70            - '-dss 1'
71    selection_other_default_actions_allow:
72        ScriptBlockText|contains: 'Set-MpPreference'
73    selection_other_default_actions_func:
74        ScriptBlockText|contains:
75            - 'HighThreatDefaultAction Allow'
76            - 'htdefac Allow'
77            - 'LowThreatDefaultAction Allow'
78            - 'ltdefac Allow'
79            - 'ModerateThreatDefaultAction Allow'
80            - 'mtdefac Allow'
81            - 'SevereThreatDefaultAction Allow'
82            - 'stdefac Allow'
83    condition: all of selection_options_disabling_* or all of selection_other_default_actions_*
84falsepositives:
85    - Legitimate PowerShell scripts that disable Windows Defender for troubleshooting purposes. Must be investigated.
86level: high