Windows Impair Defense Disable PUA Protection
Description
The following analytic identifies a modification in the Windows registry to disable Windows Defender PUA protection. Setting PUAProtection to 0 typically disables the detection and protection against Potentially Unwanted Applications by Microsoft Defender Antivirus. Potentially Unwanted Applications include software that may not be inherently malicious but could exhibit behaviors that users may find undesirable, such as adware, browser toolbars, or software bundlers. Disabling this feature might be preferred in certain situations, but it's essential to consider potential security implications. Enabling PUA protection provides an additional layer of defense against software that might negatively impact user experience or security.
- Type: TTP
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint
- Last Updated: 2024-01-08
- Author: Teoderick Contreras, Splunk
- ID: fbfef407-cfee-4866-88c1-f8de1c16147c
Annotations
ATT&CK
Kill Chain Phase
- Exploitation
NIST
- DE.CM
CIS20
- CIS 10
CVE
Search
1
2
3
4
5
6
| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Registry where Registry.registry_path= "*\\Windows Defender\\PUAProtection" Registry.registry_value_data="0x00000000" by Registry.registry_key_name Registry.user Registry.registry_path Registry.registry_value_data Registry.action Registry.dest
| `drop_dm_object_name(Registry)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_impair_defense_disable_pua_protection_filter`
Macros
The SPL above uses the following Macros:
windows_impair_defense_disable_pua_protection_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Required fields
List of fields required to use this analytic.
- _time
- Registry.registry_key_name
- Registry.registry_value_name
- Registry.dest
- Registry.user
- Registry.registry_path
- Registry.action
How To Implement
To successfully implement this search you need to be ingesting information on process that include the name of the process responsible for the changes from your endpoints into the Endpoint
datamodel in the Registry
node.
Known False Positives
It is unusual to turn this feature off a Windows system since it is a default security control, although it is not rare for some policies to disable it. Although no false positives have been identified, use the provided filter macro to tune the search.
Associated Analytic Story
RBA
Risk Score | Impact | Confidence | Message |
---|---|---|---|
49.0 | 70 | 70 | Windows Defender PUA protection set to disable on $dest$. |
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
Reference
- https://x.com/malmoeb/status/1742604217989415386?s=20
- https://github.com/undergroundwires/privacy.sexy
Test Dataset
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 | version: 1