Potentially Suspicious Electron Application CommandLine

SIGMA detection rule by frack113, Nasreddine Bencherchali (Nextron Systems) · NOASSERTION

Detects potentially suspicious CommandLine of electron apps (teams, discord, slack, etc.). This could be a sign of abuse to proxy execution through a signed binary.

title: Potentially Suspicious Electron Application CommandLine
id: 378a05d8-963c-46c9-bcce-13c7657eac99
related:
    - id: f26eb764-fd89-464b-85e2-dc4a8e6e77b8
      type: similar
status: test
description: Detects potentially suspicious CommandLine of electron apps (teams, discord, slack, etc.). This could be a sign of abuse to proxy execution through a signed binary.
references:
    - https://positive.security/blog/ms-officecmd-rce
    - https://lolbas-project.github.io/lolbas/Binaries/Teams/
    - https://lolbas-project.github.io/lolbas/Binaries/Msedge/
    - https://lolbas-project.github.io/lolbas/Binaries/msedgewebview2/
    - https://medium.com/@MalFuzzer/one-electron-to-rule-them-all-dc2e9b263daf
    - https://chromium.googlesource.com/chromium/chromium/+/master/content/public/common/content_switches.cc
author: frack113, Nasreddine Bencherchali (Nextron Systems)
date: 2023-09-05
modified: 2023-11-09
tags:
    - attack.execution
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith:
              # Add more electron based app to the list
              - '\chrome.exe'
              - '\code.exe'
              - '\discord.exe'
              - '\GitHubDesktop.exe'
              - '\keybase.exe'
              - '\msedge_proxy.exe'
              - '\msedge.exe'
              - '\msedgewebview2.exe'
              - '\msteams.exe'
              - '\slack.exe'
              - '\Teams.exe'
        - OriginalFileName:
              # Add more electron based app to the list
              - 'chrome.exe'
              - 'code.exe'
              - 'discord.exe'
              - 'GitHubDesktop.exe'
              - 'keybase.exe'
              - 'msedge_proxy.exe'
              - 'msedge.exe'
              - 'msedgewebview2.exe'
              - 'msteams.exe'
              - 'slack.exe'
              - 'Teams.exe'
    selection_cli:
        CommandLine|contains:
            - '--browser-subprocess-path'
            - '--gpu-launcher'
            - '--renderer-cmd-prefix'
            - '--utility-cmd-prefix'
    condition: all of selection_*
falsepositives:
    - Legitimate usage for debugging purposes
# Increase the level once FP rate is known better (see status)
level: medium

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e645a99f-fbac-4a0f-a685-6715330dd14b

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Executable code, not a declarative rule

This submission is arbitrary [[ currentRule.format ? currentRule.format.toUpperCase() : '' ]] code, not a declarative detection rule — review it as you would any script before running it, and note that it cannot be safely aggregated or auto-executed alongside YARA/Sigma/Suricata/CRS rules.

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Format & documentation suggestions

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