ID | Technique | Tactic |
---|---|---|
T1021 | Remote Services | Lateral Movement |
T1021.006 | Windows Remote Management | Lateral Movement |
Detection: Interactive Session on Remote Endpoint with PowerShell
Description
The following analytic detects the use of the Enter-PSSession
cmdlet to establish an interactive session on a remote endpoint via the WinRM protocol. It leverages PowerShell Script Block Logging (EventCode=4104) to identify this activity by searching for specific script block text patterns. This behavior is significant as it may indicate lateral movement or remote code execution attempts by adversaries. If confirmed malicious, this activity could allow attackers to execute commands remotely, potentially leading to further compromise of the network and unauthorized access to sensitive information.
Search
1`powershell` EventCode=4104 (ScriptBlockText="*Enter-PSSession*" AND ScriptBlockText="*-ComputerName*")
2| stats count min(_time) as firstTime max(_time) as lastTime by EventCode ScriptBlockText Computer UserID
3| rename Computer as dest
4| rename UserID as user
5| `security_content_ctime(firstTime)`
6| `security_content_ctime(lastTime)`
7| `interactive_session_on_remote_endpoint_with_powershell_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") |
interactive_session_on_remote_endpoint_with_powershell_filter | search * |
interactive_session_on_remote_endpoint_with_powershell_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 analytic, you will need to enable PowerShell Script Block Logging on some or all endpoints. Additional setup instructions can be found https://docs.splunk.com/Documentation/UBA/5.0.4.1/GetDataIn/AddPowerShell#Configure_module_logging_for_PowerShell.
Known False Positives
Administrators may leverage WinRM and Enter-PSSession
for administrative and troubleshooting tasks. This activity is usually limited to a small set of hosts or users. In certain environments, tuning may not be possible.
Associated Analytic Story
Risk Based Analytics (RBA)
Risk Message | Risk Score | Impact | Confidence |
---|---|---|---|
An interactive session was opened on a remote endpoint from $dest$ | 45 | 90 | 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: 6