Start Up During Safe Mode Boot
Description
This search is to detect a modification or registry add to the safeboot registry as an autostart mechanism. This technique was seen in some ransomware to automatically execute its code upon a safe mode boot.
- Type: TTP
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint- Datasource: Splunk Add-on for Sysmon
- Last Updated: 2022-01-26
- Author: Teoderick Contreras, Splunk
- ID: c6149154-c9d8-11eb-9da7-acde48001122
Annotations
ATT&CK
Kill Chain Phase
- Exploitation
NIST
CIS20
CVE
Search
1
2
3
4
5
6
7
8
9
10
11
| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Registry where Registry.registry_path="*\\System\\CurrentControlSet\\Control\\SafeBoot\\Minimal\*" by _time span=1h Registry.dest Registry.user Registry.registry_path Registry.registry_value_name Registry.registry_value_data Registry.process_guid
| `drop_dm_object_name(Registry)`
|rename process_guid as proc_guid
|join proc_guid, _time [
| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Processes by _time span=1h Processes.process_id Processes.process_name Processes.process Processes.dest Processes.parent_process_name Processes.parent_process Processes.process_guid
| `drop_dm_object_name(Processes)`
|rename process_guid as proc_guid
| fields _time dest user parent_process_name parent_process process_name process_path process proc_guid registry_path registry_value_name registry_value_data]
| table _time dest user parent_process_name parent_process process_name process_path process proc_guid registry_path registry_value_name registry_value_data
| `start_up_during_safe_mode_boot_filter`
Macros
The SPL above uses the following Macros:
Note that start_up_during_safe_mode_boot_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Required field
- _time
- Registry.registry_path
- Registry.registry_key_name
- Registry.registry_value_name
- Registry.dest
How To Implement
To successfully implement this search, you must be ingesting data that records registry activity from your hosts to populate the endpoint data model in the registry node. This is typically populated via endpoint detection-and-response product, such as Carbon Black or endpoint data sources, such as Sysmon. The data used for this search is typically generated via logs that report reads and writes to the registry.
Known False Positives
updated windows application needed in safe boot may used this registry
Associated Analytic story
RBA
Risk Score | Impact | Confidence | Message |
---|---|---|---|
42.0 | 60 | 70 | Safeboot registry $registry_path$ was added or modified with a new value $registry_value_name$ on $dest$ |
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: 2