Detection: Windows Event For Service Disabled

Updated Date: 2024-05-11 ID: 9c2620a8-94a1-11ec-b40c-acde48001122 Author: Teoderick Contreras, Splunk Type: Hunting Product: Splunk Enterprise Security

Description

The following analytic detects when a Windows service is modified from a start type to disabled. It leverages system event logs, specifically EventCode 7040, to identify this change. This activity is significant because adversaries often disable security or other critical services to evade detection and maintain control over a compromised host. If confirmed malicious, this action could allow attackers to bypass security defenses, leading to further exploitation and persistence within the environment.

Search

1`wineventlog_system` EventCode=7040  EventData_Xml="*disabled*" 
2| stats count min(_time) as firstTime max(_time) as lastTime by Computer EventCode Name UserID service ServiceName 
3| rename Computer as dest 
4| `security_content_ctime(firstTime)` 
5| `security_content_ctime(lastTime)` 
6| `windows_event_for_service_disabled_filter`

Data Source

Name	Platform	Sourcetype	Source	Supported App
Windows Event Log System 7040	Windows	`'xmlwineventlog'`	`'XmlWinEventLog:System'`	N/A

Macros Used

Name	Value
security_content_ctime	`convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)`
windows_event_for_service_disabled_filter	`search *`

windows_event_for_service_disabled_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
T1562.001	Disable or Modify Tools	Defense Evasion
T1562	Impair Defenses	Defense Evasion

KillChainPhase.EXPLOITAITON

NistCategory.DE_AE

Cis18Value.CIS_10

Aquatic Panda

BRONZE BUTLER

Ember Bear

FIN6

Gamaredon Group

Gorgon Group

Indrik Spider

Kimsuky

Lazarus Group

Magic Hound

MuddyWater

Putter Panda

Rocke

TA2541

TA505

TeamTNT

Turla

Wizard Spider

Magic Hound

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 Risk Event	False

This configuration file applies to all detections of type hunting.

Implementation

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.

Known False Positives

Windows service update may cause this event. In that scenario, filtering is needed.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
Service $ServiceName$ was disabled on $dest$	36	60	60

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

https://blog.talosintelligence.com/2018/02/olympic-destroyer.html

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	✅ Passing	N/A	N/A	N/A
Unit	✅ Passing	Dataset	`XmlWinEventLog:System`	`XmlWinEventLog`
Integration	✅ Passing	Dataset	`XmlWinEventLog:System`	`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