ID | Technique | Tactic |
---|---|---|
T1027 | Obfuscated Files or Information | Defense Evasion |
T1027.005 | Indicator Removal from Tools | Defense Evasion |
Detection: Powershell Enable SMB1Protocol Feature
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.
Search
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 | '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
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 |
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 |
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