The following analytic identifies a windows update service being disabled in Windows OS. This technique is being abused by adversaries or threat actors to add defense mechanisms to their malware implant in the targeted host. Disabling windows update will put the compromised host vulnerable in some zero day exploit or even some update features against threats. RedLine Stealer kills this service as part of its defense evasion mechanism.
- Type: Anomaly
Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Last Updated: 2023-04-21
- Author: Teoderick Contreras, Splunk
- ID: 0dc25c24-6fcf-456f-b08b-dd55a183e4de
Kill Chain Phase
- Actions On Objectives
- CIS 10
1 2 3 4 5 6 `wineventlog_system` EventCode=7040 (service_name IN ("Update Orchestrator Service for Windows Update", "WaaSMedicSvc", "Windows Update") OR param1 IN ("UsoSvc", "WaaSMedicSvc", "wuauserv")) AND (param3=disabled OR start_mode = disabled) | stats count min(_time) as firstTime max(_time) as lastTime by Computer Error_Code service_name start_mode param1 param2 param3 param4 | rename Computer as dest | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_service_stop_win_updates_filter`
The SPL above uses the following Macros:
windows_service_stop_win_updates_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
List of fields required to use this analytic.
How To Implement
To successfully implement this search, you need to be ingesting logs with the Service name, Service File Name Service Start type, and Service Type from your endpoints (like Windows system.log Event ID 7040)
Known False Positives
Network administrator may disable this services as part of its audit process within the network. Filter is needed.
Associated Analytic Story
|49.0||70||70||Windows update services $service_name$ was being disabled 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.
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