Detection: Disabling CMD Application

Updated Date: 2024-09-30 ID: ff86077c-9212-11eb-a1e6-acde48001122 Author: Steven Dick, Teoderick Contreras, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects modifications to the registry that disable the CMD prompt application. It leverages data from the Endpoint.Registry data model, specifically looking for changes to the "DisableCMD" registry value. This activity is significant because disabling CMD can hinder an analyst's ability to investigate and remediate threats, a tactic often used by malware such as RATs, Trojans, or Worms. If confirmed malicious, this could prevent security teams from using CMD for directory and file traversal, complicating incident response and allowing the attacker to maintain persistence.

Search

1
2| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Registry WHERE (Registry.registry_path= "*\\SOFTWARE\\Policies\\Microsoft\\Windows\\System\\DisableCMD" 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 
3| `drop_dm_object_name(Registry)` 
4| where isnotnull(registry_value_data) 
5| `security_content_ctime(firstTime)` 
6| `security_content_ctime(lastTime)` 
7| `disabling_cmd_application_filter`

Data Source

Name	Platform	Sourcetype	Source
Sysmon EventID 12	Windows	`'xmlwineventlog'`	`'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'`
Sysmon EventID 13	Windows	`'xmlwineventlog'`	`'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'`

Macros Used

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

disabling_cmd_application_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
T1112	Modify Registry	Defense Evasion

KillChainPhase.EXPLOITAITON

NistCategory.DE_CM

Cis18Value.CIS_10

Agrius

Aquatic Panda

BRONZE BUTLER

Ember Bear

FIN6

Gamaredon Group

Gorgon Group

INC Ransom

Indrik Spider

Kimsuky

Lazarus Group

Magic Hound

MuddyWater

Play

Putter Panda

Rocke

Saint Bear

TA2541

TA505

TeamTNT

Turla

Wizard Spider

Magic Hound

APT19

APT32

APT38

APT41

Aquatic Panda

Blue Mockingbird

Dragonfly

Earth Lusca

Ember Bear

FIN8

Gamaredon Group

Gorgon Group

Indrik Spider

Kimsuky

LuminousMoth

Magic Hound

Patchwork

Saint Bear

Silence

TA505

Threat Group-3390

Turla

Volt Typhoon

Wizard Spider

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

admin may disable this application for non technical user.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
The Windows command prompt was disabled on $dest$ by $user$.	25	50	50

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://any.run/report/ea4ea08407d4ee72e009103a3b77e5a09412b722fdef67315ea63f22011152af/a866d7b1-c236-4f26-a391-5ae32213dfc4#registry

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: 7