Detection rules › Splunk

Visual Studio Code Tunnel Execution (PowerShell)

Source
github.com/anvilogic-forge/armory

Adversaries may communicate using application layer protocols associated with web traffic to avoid detection/network filtering by blending in with existing traffic. Commands to the remote system, and often the results of those commands, will be embedded within the protocol traffic between the client and server. This use case detects the execution of Visual Studio Code tunnel in attempt to establish a C2 channel, accounting for instances where the binary has been renamed.

MITRE ATT&CK coverage

References

Telemetry coverage

Rule body

id: '40420.73845'
title: Visual Studio Code Tunnel Execution
description: Adversaries may communicate using application layer protocols associated
  with web traffic to avoid detection/network filtering by blending in with existing
  traffic. Commands to the remote system, and often the results of those commands,
  will be embedded within the protocol traffic between the client and server. This
  use case detects the execution of Visual Studio Code tunnel in attempt to establish
  a C2 channel, accounting for instances where the binary has been renamed.
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_powershell` ((TERM(EventCode=4103)
  OR "<EventID>4103<") OR (TERM(EventCode=4104) OR "<EventID>4104<")) "tunnel" OR
  ("tunnel" ("--name " "--accept-server-license-terms") OR "--cli-data-dir") | where
  match(process, "(?i)\.exe(\x22)?\s+tunnel\s?") or ((match(process, "\.exe(\x22)?\s+tunnel\s?$")
  and like(process, "%--name %") and like(process, "%--accept-server-license-terms%"))
  or like(process, "%--cli-data-dir%") | table _time, host, user, process, process_*
  | bin span=1s | stats values(*) as * by _time, host '
techniques:
- command-and-control:application layer protocol:web protocols
technique_id:
- T1071.001
data_category:
- PowerShell logs
references:
- https://detection.fyi/sigmahq/sigma/windows/process_creation/proc_creation_win_vscode_tunnel_execution/
- https://attack.mitre.org/techniques/T1071/001/
- https://www.sentinelone.com/labs/operation-digital-eye-chinese-apt-compromises-critical-digital-infrastructure-via-visual-studio-code-tunnels/