Windows Disable Lock Workstation Feature Through Registry
Description
This analytic is to detect a suspicious registry modification to disable Lock Computer windows features. This registry modification prevent the user from locking its screen or computer that are being abused by several malware for example ransomware. This technique was used by threat actor to make its payload more impactful to the compromised host.
- Type: Anomaly
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint
- Last Updated: 2023-04-27
- Author: Steven Dick, Teoderick Contreras, Splunk
- ID: c82adbc6-9f00-11ec-a81f-acde48001122
Annotations
Kill Chain Phase
- Exploitation
NIST
- DE.AE
CIS20
- CIS 10
CVE
Search
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| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Registry WHERE (Registry.registry_path= "*\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\DisableLockWorkstation" Registry.registry_value_data = "0x00000001") BY _time span=1h Registry.dest Registry.user Registry.registry_path Registry.registry_key_name Registry.registry_value_name Registry.registry_value_data Registry.process_guid
| `drop_dm_object_name(Registry)`
| where isnotnull(registry_value_data)
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_disable_lock_workstation_feature_through_registry_filter`
Macros
The SPL above uses the following Macros:
windows_disable_lock_workstation_feature_through_registry_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.dest
- Registry.registry_value_name
- Registry.registry_key_name
- Registry.registry_path
- Registry.registry_value_data
- Registry.process_guid
How To Implement
To successfully implement this search, you need to be ingesting logs with the registry value name, registry path, and registry value data from your endpoints. If you are using Sysmon, you must have at least version 2.0 of the offical Sysmon TA. https://splunkbase.splunk.com/app/5709
Known False Positives
unknown
Associated Analytic Story
RBA
Risk Score | Impact | Confidence | Message |
---|---|---|---|
49.0 | 70 | 70 | Registry modification in "DisableLockWorkstation" 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://www.bleepingcomputer.com/news/security/in-dev-ransomware-forces-you-do-to-survey-before-unlocking-computer/
- https://heimdalsecurity.com/blog/fatalrat-targets-telegram/
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: 3