From fb3a72b43365f7d2353fd9c520efe25b8a336464 Mon Sep 17 00:00:00 2001
From: frack113 <62423083+frack113@users.noreply.github.com>
Date: Mon, 13 May 2024 13:18:39 +0200
Subject: [PATCH] Merge PR #4852 from @frack113 - Add `Potential Packet Capture
 Activity Via Start-NetEventSession - ScriptBlock`

new: Potential Packet Capture Activity Via Start-NetEventSession - ScriptBlock

---------

Co-authored-by: nasbench <8741929+nasbench@users.noreply.github.com>
---
 .../posh_ps_packet_capture.yml                | 28 +++++++++++++++++++
 1 file changed, 28 insertions(+)
 create mode 100644 rules/windows/powershell/powershell_script/posh_ps_packet_capture.yml

diff --git a/rules/windows/powershell/powershell_script/posh_ps_packet_capture.yml b/rules/windows/powershell/powershell_script/posh_ps_packet_capture.yml
new file mode 100644
index 000000000..cb70c5b3b
--- /dev/null
+++ b/rules/windows/powershell/powershell_script/posh_ps_packet_capture.yml
@@ -0,0 +1,28 @@
+title: Potential Packet Capture Activity Via Start-NetEventSession - ScriptBlock
+id: da34e323-1e65-42db-83be-a6725ac2caa3
+status: experimental
+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