Detection: Powershell Disable Security Monitoring

Updated Date: 2025-07-10 ID: c148a894-dd93-11eb-bf2a-acde48001122 Author: Michael Haag, Nasreddine Bencherchali, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic identifies attempts to disable Windows Defender real-time behavior monitoring via PowerShell commands. It detects the use of specific Set-MpPreference parameters that disable various security features. This activity is significant as it is commonly used by malware such as RATs, bots, or Trojans to evade detection by disabling antivirus protections. If confirmed malicious, this action could allow an attacker to operate undetected, leading to potential data exfiltration, further system compromise, or persistent access within the environment.

Search

 1
 2| tstats `security_content_summariesonly`
 3  count min(_time) as firstTime
 4        max(_time) as lastTime
 5from datamodel=Endpoint.Processes where
 6`process_powershell`
 7Processes.process="*Set-MpPreference*"
 8(
 9  Processes.process IN (
10    "*DisableArchiveScanning*",
11    "*DisableBehaviorMonitoring*",
12    "*DisableBlockAtFirstSeen*",
13    "*DisableCatchupFullScan*",
14    "*DisableCatchupQuickScan*",
15    "*DisableIOAVProtection*",
16    "*DisableRealtimeMonitoring*",
17    "*DisableRemovableDriveScanning*",
18    "*DisableRestorePoint*",
19    "*DisableScanningMappedNetworkDrivesForFullScan*",
20    "*DisableScanningNetworkFiles*",
21    "*DisableScriptScanning*",
22    "*drdsc*",
23    "*dsnf *",
24    "*drtm *",
25    "*dioavp *",
26    "*dscrptsc *",
27    "*dbaf *",
28    "*darchsc *",
29    "*dcfsc *",
30    "*dbm *"
31  )
32  Processes.process IN (
33    "* $true*",
34    "* 1*"
35  )
36)
37OR
38(
39  Processes.process = "*PUAProtection*"
40  Processes.process = "*disable*"
41)
42OR
43(
44  Processes.process = "*CloudBlockLevel*"
45  Processes.process IN (
46    "* $false*", 
47    "* 0*"
48  )
49)
50by Processes.action Processes.dest Processes.original_file_name Processes.parent_process
51   Processes.parent_process_exec Processes.parent_process_guid Processes.parent_process_id
52   Processes.parent_process_name Processes.parent_process_path Processes.process Processes.process_exec
53   Processes.process_guid Processes.process_hash Processes.process_id Processes.process_integrity_level
54   Processes.process_name Processes.process_path Processes.user Processes.user_id Processes.vendor_product
55
56
57| `drop_dm_object_name(Processes)`
58
59| `security_content_ctime(firstTime)`
60
61| `security_content_ctime(lastTime)`
62
63| `powershell_disable_security_monitoring_filter`

Data Source

Name	Platform	Sourcetype	Source
CrowdStrike ProcessRollup2	N/A	`'crowdstrike:events:sensor'`	`'crowdstrike'`
Sysmon EventID 1	Windows	`'XmlWinEventLog'`	`'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'`
Windows Event Log Security 4688	Windows	`'XmlWinEventLog'`	`'XmlWinEventLog:Security'`

Macros Used

Name	Value
process_powershell	`(Processes.process_name=pwsh.exe OR Processes.process_name=powershell.exe OR Processes.process_name=powershell_ise.exe OR Processes.original_file_name=pwsh.dll OR Processes.original_file_name=PowerShell.EXE OR Processes.original_file_name=powershell_ise.EXE)`
powershell_disable_security_monitoring_filter	`search *`

powershell_disable_security_monitoring_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK

+ Kill Chain Phases

+ NIST

+ CIS

- Threat Actors

ID	Technique	Tactic
T1562.001	Disable or Modify Tools	Defense Evasion

Exploitation

DE.CM

CIS 10

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting	Value
Disabled	true
Cron Schedule	`0 * * * *`
Earliest Time	`-70m@m`
Latest Time	`-10m@m`
Schedule Window	`auto`
Creates Notable	Yes
Rule Title	`%name%`
Rule Description	`%description%`
Notable Event Fields	user, dest
Creates Risk Event	True

This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.

Implementation

The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the Processes node of the Endpoint data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.

Known False Positives

Limited false positives. However, tune based on scripts that may perform this action.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message:

Windows Defender Real-time Behavior Monitoring disabled on $dest$

Risk Object	Risk Object Type	Risk Score	Threat Objects
dest	system	25	No Threat Objects

References

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	✅ Passing	N/A	N/A	N/A
Unit	✅ Passing	Dataset	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`	`XmlWinEventLog`
Integration	✅ Passing	Dataset	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`	`XmlWinEventLog`

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

Source: GitHub | Version: 11