Potential Packet Capture Activity Via Start-NetEventSession - ScriptBlock

Description

Detects the execution of powershell scripts with calls to the "Start-NetEventSession" cmdlet. Which allows an attacker to start event and packet capture for a network event session. Adversaries may attempt to capture network to gather information over the course of an operation. Data captured via this technique may include user credentials, especially those sent over an insecure, unencrypted protocol.

Query · sigma

selection:
  ScriptBlockText|contains: Start-NetEventSession
condition: selection

Known false positives

  • Legitimate network diagnostic scripts.
Raw source Potential Packet Capture Activity Via Start-NetEventSession - ScriptBlock · Sigma
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Published by SigmaHQ/sigma ↗, licensed under Detection Rule License 1.1 ↗. Reproduced here unmodified. 
title: Potential Packet Capture Activity Via Start-NetEventSession - ScriptBlock
id: da34e323-1e65-42db-83be-a6725ac2caa3
status: test
description: |
    Detects the execution of powershell scripts with calls to the "Start-NetEventSession" cmdlet. Which allows an attacker to start event and packet capture for a network event session.
    Adversaries may attempt to capture network to gather information over the course of an operation.
    Data captured via this technique may include user credentials, especially those sent over an insecure, unencrypted protocol.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/5f866ca4517e837c4ea576e7309d0891e78080a8/atomics/T1040/T1040.md#atomic-test-16---powershell-network-sniffing
    - https://github.com/0xsyr0/Awesome-Cybersecurity-Handbooks/blob/7b8935fe4c82cb64d61343de1a8b2e38dd968534/handbooks/10_post_exploitation.md
    - https://github.com/forgottentq/powershell/blob/9e616363d497143dc955c4fdce68e5c18d28a6cb/captureWindows-Endpoint.ps1#L13
author: frack113
date: 2024-05-12
tags:
    - attack.credential-access
    - attack.discovery
    - attack.t1040
logsource:
    product: windows
    category: ps_script
    definition: 'Requirements: Script Block Logging must be enabled'
detection:
    selection:
        ScriptBlockText|contains: 'Start-NetEventSession'
    condition: selection
falsepositives:
    - Legitimate network diagnostic scripts.
level: medium

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