Unload Sysmon Filter Driver
Description
Attackers often disable security tools to avoid detection. This search looks for the usage of process fltMC.exe
to unload a Sysmon Driver that will stop sysmon from collecting the data.
- Type: TTP
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint
- Last Updated: 2022-06-01
- Author: Bhavin Patel, Splunk
- ID: e5928ff3-23eb-4d8b-b8a4-dcbc844fdfbe
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 values(Processes.process) as process max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.process_name=fltMC.exe AND Processes.process=*unload* AND Processes.process=*SysmonDrv* by Processes.process_name Processes.process_id Processes.parent_process_name Processes.process Processes.dest Processes.user
| `drop_dm_object_name("Processes")`
| `security_content_ctime(firstTime)`
|`security_content_ctime(lastTime)`
|`unload_sysmon_filter_driver_filter`
| table firstTime lastTime dest user count process_name process_id parent_process_name process
Macros
The SPL above uses the following Macros:
unload_sysmon_filter_driver_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
- Processes.process_name
- Processes.process
- Processes.process_id
- Processes.parent_process_name
- Processes.dest
- Processes.user
How To Implement
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
Unknown at the moment
Associated Analytic Story
RBA
Risk Score | Impact | Confidence | Message |
---|---|---|---|
45.0 | 50 | 90 | Possible Sysmon filter driver unloading 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
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: 4