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Description

The following analytic detects the execution of the Invoke-ShareFinder PowerShell cmdlet from PowerView. This detection leverages PowerShell Script Block Logging to identify instances where this specific command is executed. Monitoring this activity is crucial as it indicates an attempt to enumerate network file shares, which may contain sensitive information such as backups, scripts, and credentials. If confirmed malicious, this activity could enable an attacker to escalate privileges or move laterally within the network, potentially compromising additional systems and sensitive data.

  • Type: TTP

  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

  • Last Updated: 2024-05-18
  • Author: Mauricio Velazco, Splunk
  • ID: a44c0be1-d7ab-41e4-92fd-aa9af4fe232c

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1135 Network Share Discovery Discovery
Kill Chain Phase
  • Exploitation
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


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`powershell` EventCode=4104  (ScriptBlockText=Invoke-ShareFinder*) 
| stats count min(_time) as firstTime max(_time) as lastTime by Opcode Computer UserID EventCode ScriptBlockText 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `windows_file_share_discovery_with_powerview_filter`

Macros

The SPL above uses the following Macros:

:information_source: windows_file_share_discovery_with_powerview_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • _time
  • EventCode
  • ScriptBlockText
  • Opcode
  • Computer
  • UserID

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.=

Known False Positives

Security teams may leverage PowerView proactively to identify and remediate sensitive file shares. Filter as needed.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
48.0 60 80 Invoke-ShareFinder commandlet was executed on $Computer$

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

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

source | version: 2