Windows Impair Defense Disable Win Defender Signature Retirement
Description
The following analytic identifies a modification in the Windows registry to disable windows defender Signature Retirement. The DisableSignatureRetirement registry setting in Windows Defender controls the retirement or expiration of antivirus signatures used by Windows Defender Antivirus. When DisableSignatureRetirement is set to 1, it usually indicates that Windows Defender won't automatically retire or expire antivirus signatures. Antivirus signatures are files containing information about known malware and are used by Windows Defender to detect and protect against threats. Disabling signature retirement might prevent Windows Defender from automatically removing or retiring older or less relevant antivirus signatures. This can potentially increase the number of signatures in use and might impact system resources or the effectiveness of threat detection.
- Type: TTP
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint
- Last Updated: 2024-01-08
- Author: Teoderick Contreras, Splunk
- ID: 7567a72f-bada-489d-aef1-59743fb64a66
Annotations
ATT&CK
Kill Chain Phase
- Exploitation
NIST
- DE.CM
CIS20
- CIS 10
CVE
Search
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| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Registry where Registry.registry_path= "*\\Windows Defender\\NIS\\Consumers\\IPS\\DisableSignatureRetirement" Registry.registry_value_data="0x00000001" 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_win_defender_signature_retirement_filter`
Macros
The SPL above uses the following Macros:
windows_impair_defense_disable_win_defender_signature_retirement_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 DisableSignatureRetirement registry is set to enable 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