Detection: Powershell Enable SMB1Protocol Feature

Updated Date: 2024-09-30 ID: afed80b2-d34b-11eb-a952-acde48001122 Author: Teoderick Contreras, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects the enabling of the SMB1 protocol via powershell.exe. It leverages PowerShell script block logging (EventCode 4104) to identify the execution of the Enable-WindowsOptionalFeature cmdlet with the SMB1Protocol parameter. This activity is significant because enabling SMB1 can facilitate lateral movement and file encryption by ransomware, such as RedDot. If confirmed malicious, this action could allow an attacker to propagate through the network, encrypt files, and potentially disrupt business operations.

1`powershell` EventCode=4104 ScriptBlockText = "*Enable-WindowsOptionalFeature*" ScriptBlockText = "*SMB1Protocol*" 
2| stats count min(_time) as firstTime max(_time) as lastTime by EventCode ScriptBlockText Computer UserID 
3| `security_content_ctime(firstTime)` 
4| `security_content_ctime(lastTime)` 
5| `powershell_enable_smb1protocol_feature_filter`

Data Source

Name Platform Sourcetype Source
Powershell Script Block Logging 4104 Windows icon Windows 'xmlwineventlog' 'XmlWinEventLog:Microsoft-Windows-PowerShell/Operational'

Macros Used

Name Value
powershell (source=WinEventLog:Microsoft-Windows-PowerShell/Operational OR source="XmlWinEventLog:Microsoft-Windows-PowerShell/Operational")
powershell_enable_smb1protocol_feature_filter search *
powershell_enable_smb1protocol_feature_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
T1027 Obfuscated Files or Information Defense Evasion
T1027.005 Indicator Removal from Tools Defense Evasion
KillChainPhase.EXPLOITAITON
NistCategory.DE_CM
Cis18Value.CIS_10
APT-C-36
APT3
APT37
APT41
BackdoorDiplomacy
BlackOasis
Earth Lusca
GALLIUM
Gallmaker
Gamaredon Group
Ke3chang
Kimsuky
Moonstone Sleet
Mustang Panda
RedCurl
Rocke
Sandworm Team
Windshift
APT3
Deep Panda
GALLIUM
OilRig
Patchwork
Turla

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 powershell logs from your endpoints. make sure you enable needed registry to monitor this event.

Known False Positives

network operator may enable or disable this windows feature.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message Risk Score Impact Confidence
Powershell Enable SMB1Protocol Feature on $Computer$ 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

Detection Testing

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