Detection: Windows Service Creation Using Registry Entry

Updated Date: 2024-05-30 ID: 25212358-948e-11ec-ad47-acde48001122 Author: Steven Dick, Teoderick Contreras, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects the modification of registry keys that define Windows services using reg.exe. This detection leverages Splunk to search for specific keywords in the registry path, value name, and value data fields. This activity is significant because it indicates potential unauthorized changes to service configurations, a common persistence technique used by attackers. If confirmed malicious, this could allow an attacker to maintain access, escalate privileges, or move laterally within the network, leading to data theft, ransomware, or other damaging outcomes.

1
2| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Registry WHERE (Registry.registry_path="*\\SYSTEM\\CurrentControlSet\\Services*" Registry.registry_value_name = ImagePath) 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 
3| `drop_dm_object_name(Registry)` 
4| where isnotnull(registry_value_data) 
5| `security_content_ctime(firstTime)` 
6| `security_content_ctime(lastTime)` 
7| `windows_service_creation_using_registry_entry_filter`

Data Source

Name Platform Sourcetype Source Supported App
Sysmon EventID 12 Windows icon Windows 'xmlwineventlog' 'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational' N/A

Macros Used

Name Value
security_content_ctime convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)
windows_service_creation_using_registry_entry_filter search *
windows_service_creation_using_registry_entry_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK
+ Kill Chain Phases
+ NIST
+ CIS
- Threat Actors
ID Technique Tactic
T1574.011 Services Registry Permissions Weakness Defense Evasion
KillChainPhase.EXPLOITAITON
KillChainPhase.INSTALLATION
NistCategory.DE_CM
Cis18Value.CIS_10

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting Value
Disabled true
Cron Schedule 0 * * * *
Earliest Time -70m@m
Latest Time -10m@m
Schedule Window auto
Creates Notable Yes
Rule Title %name%
Rule Description %description%
Notable Event Fields user, dest
Creates Risk Event True
This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.

Implementation

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

Third party tools may used this technique to create services but not so common.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message Risk Score Impact Confidence
A Windows Service was created on a endpoint from $dest$ using a registry entry 64 80 80
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

References

Detection Testing

Test Type Status Dataset Source Sourcetype
Validation ✅ Passing N/A N/A N/A
Unit ✅ Passing Dataset XmlWinEventLog:Microsoft-Windows-Sysmon/Operational xmlwineventlog
Integration ✅ Passing Dataset XmlWinEventLog:Microsoft-Windows-Sysmon/Operational xmlwineventlog

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: GitHub | Version: 4