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Description

The following analytic utilizes PowerShell Script Block Logging (EventCode=4104) to identify the execution of the Get-NetTcpconnection commandlet. This commandlet is used to return a listing of network connections on a compromised system. Red Teams and adversaries alike may use this commandlet for situational awareness and Active Directory Discovery.

  • Type: Hunting
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2021-09-10
  • Author: Mauricio Velazco, Splunk
  • ID: 091712ff-b02a-4d43-82ed-34765515d95d

ATT&CK

ID Technique Tactic
T1049 System Network Connections Discovery Discovery
`powershell` EventCode=4104 (Message = "*Get-NetTcpconnection*") 
| stats count min(_time) as firstTime max(_time) as lastTime by EventCode Message ComputerName User 
| `security_content_ctime(firstTime)` 
| `getnettcpconnection_with_powershell_script_block_filter`

Associated Analytic Story

How To Implement

To successfully implement this analytic, you will need to enable PowerShell Script Block Logging on some or all endpoints. Additional setup here https://docs.splunk.com/Documentation/UBA/5.0.4.1/GetDataIn/AddPowerShell#Configure_module_logging_for_PowerShell.

Required field

  • _time
  • EventCode
  • Message
  • ComputerName
  • User

Kill Chain Phase

  • Reconnaissance

Known False Positives

Administrators or power users may use this PowerShell commandlet for troubleshooting.

RBA

Risk Score Impact Confidence Message
15.0 30 50 Network Connection discovery on $dest$ by $user$

Reference

Test Dataset

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

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