Detection rules › Sigma
Suspicious Electron Application Child Processes
Detects suspicious child processes of electron apps (teams, discord, slack, etc.). This could be a potential sign of ".asar" file tampering (See reference section for more information) or binary execution proxy through specific CLI arguments (see related rule)
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Execution | No specific technique |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 1 | Process creation |
| Security-Auditing | Event ID 4688 | A new process has been created. |
Rule body yaml
title: Suspicious Electron Application Child Processes
id: f26eb764-fd89-464b-85e2-dc4a8e6e77b8
related:
- id: 378a05d8-963c-46c9-bcce-13c7657eac99
type: similar
status: test
description: |
Detects suspicious child processes of electron apps (teams, discord, slack, etc.). This could be a potential sign of ".asar" file tampering (See reference section for more information) or binary execution proxy through specific CLI arguments (see related rule)
references:
- https://taggart-tech.com/quasar-electron/
- https://github.com/mttaggart/quasar
- https://positive.security/blog/ms-officecmd-rce
- https://lolbas-project.github.io/lolbas/Binaries/Msedge/
- https://lolbas-project.github.io/lolbas/Binaries/Teams/
- https://lolbas-project.github.io/lolbas/Binaries/msedgewebview2/
- https://medium.com/@MalFuzzer/one-electron-to-rule-them-all-dc2e9b263daf
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-10-21
modified: 2024-07-12
tags:
- attack.execution
logsource:
category: process_creation
product: windows
detection:
selection_parent:
ParentImage|endswith:
# Add more electron based app to the list
- '\chrome.exe' # Might require additional tuning
- '\discord.exe'
- '\GitHubDesktop.exe'
- '\keybase.exe'
- '\msedge.exe'
- '\msedgewebview2.exe'
- '\msteams.exe'
- '\slack.exe'
- '\teams.exe'
# - '\code.exe' # Prone to a lot of FPs. Requires an additional baseline
selection_child_image:
Image|endswith:
# Add more suspicious/unexpected paths
- '\cmd.exe'
- '\cscript.exe'
- '\mshta.exe'
- '\powershell.exe'
- '\pwsh.exe'
- '\regsvr32.exe'
- '\whoami.exe'
- '\wscript.exe'
selection_child_paths:
Image|contains:
# Add more suspicious/unexpected paths
- ':\ProgramData\'
- ':\Temp\'
- '\AppData\Local\Temp\'
- '\Users\Public\'
- '\Windows\Temp\'
filter_optional_discord:
ParentImage|endswith: '\Discord.exe'
Image|endswith: '\cmd.exe'
CommandLine|contains: '\NVSMI\nvidia-smi.exe'
condition: selection_parent and 1 of selection_child_* and not 1 of filter_optional_*
falsepositives:
- Unknown
# Increase the level once FP rate is reduced (see status)
level: medium
Stages and Predicates
Stage 0: condition
selection_parent and 1 of selection_child_* and not 1 of filter_optional_*Stage 1: selection_parent
selection_parent:
ParentImage|endswith:
- '\chrome.exe'
- '\discord.exe'
- '\GitHubDesktop.exe'
- '\keybase.exe'
- '\msedge.exe'
- '\msedgewebview2.exe'
- '\msteams.exe'
- '\slack.exe'
- '\teams.exe'
Stage 2: selection_child_image
selection_child_image:
Image|endswith:
- '\cmd.exe'
- '\cscript.exe'
- '\mshta.exe'
- '\powershell.exe'
- '\pwsh.exe'
- '\regsvr32.exe'
- '\whoami.exe'
- '\wscript.exe'
Stage 3: selection_child_paths
selection_child_paths:
Image|contains:
- ':\ProgramData\'
- ':\Temp\'
- '\AppData\Local\Temp\'
- '\Users\Public\'
- '\Windows\Temp\'
Stage 4: not filter_optional_discord
filter_optional_discord:
ParentImage|endswith: '\Discord.exe'
Image|endswith: '\cmd.exe'
CommandLine|contains: '\NVSMI\nvidia-smi.exe'
Exclusions
Top-level NOT(...) conjuncts: predicates this rule actively suppresses.
| Field | Kind | Excluded values |
|---|---|---|
CommandLine | match | \NVSMI\nvidia-smi.exe |
Image | ends_with | \cmd.exe |
ParentImage | ends_with | \Discord.exe |
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
Image | ends_with |
|
Image | match |
|
ParentImage | ends_with |
|