Suspicious Child Processes Spawned by Browsers on macOS

Alerts on browser-launched child processes on macOS where the child is a shell or scripting/utility binary, excluding known benign browser scripts.

FreeReviewedSigma · Medium · v2

Product: macos
Category: process_creation
Author: Sohan G (D4rkCiph3r) (SigmaHQ), DRL 1.1
Published: 2023-04-05
Updated: 2026-07-31

Analysis Detection

ATT&CK techniques

Initial Access → Execution

Recon
Resource Dev
Initial Access
- T1189Drive-by Compromise
Execution
- T1059Command and Scripting Interpreter
- T1203Exploitation for Client Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule flags process creation on macOS where the parent process name indicates a web browser component (e.g., WebKit WebContent, Firefox, Chrome/Helper, Edge, Safari, Opera, Tor Browser) and the child executable path ends with common scripting or networking interpreters (bash, sh, python, perl, php, curl, wget, osascript, pwsh, etc.). Such activity matters because it can reflect code execution triggered by browser exploitation or malicious web content leading to command execution. Detection relies on process creation telemetry including parent image name and the child image path and command-line content, while filtering out known benign browser install/update/recovery utilities and Tor default configuration usage.

Reporting behind it

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Suspicious Child Processes Spawned by Browsers on macOS

Pivot detection · T1059 · 9 related

Changelog

v2
Candidate ingested via manual entry.2026-07-31
v1
No changelog recorded for this version.2026-07-30

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.

suspicious-child-process-spawned-by-browsers-on-macos-via-shell-and-script-runti-0250638a

title: Suspicious Child Processes Spawned by Browsers on macOS
id: 3e2c6947-7d45-4bb9-9d23-378be46dda4a
status: test
description: This rule flags process creation on macOS where the parent process name indicates a web browser component (e.g., WebKit WebContent, Firefox, Chrome/Helper, Edge, Safari, Opera, Tor Browser) and the child executable path ends with common scripting or networking interpreters (bash, sh, python, perl, php, curl, wget, osascript, pwsh, etc.). Such activity matters because it can reflect code execution triggered by browser exploitation or malicious web content leading to command execution. Detection relies on process creation telemetry including parent image name and the child image path and command-line content, while filtering out known benign browser install/update/recovery utilities and Tor default configuration usage.
references:
  - https://fr.slideshare.net/codeblue_jp/cb19-recent-apt-attack-on-crypto-exchange-employees-by-heungsoo-kang
  - https://github.com/elastic/detection-rules/blob/4312d8c9583be524578a14fe6295c3370b9a9307/rules/macos/execution_initial_access_suspicious_browser_childproc.toml
  - https://github.com/SigmaHQ/sigma/blob/master/rules/macos/process_creation/proc_creation_macos_susp_browser_child_process.yml
author: Sohan G (D4rkCiph3r), Huntrule Team
date: 2023-04-05
tags:
  - attack.initial-access
  - attack.execution
  - attack.t1189
  - attack.t1203
  - attack.t1059
logsource:
  category: process_creation
  product: macos
detection:
  selection:
    ParentImage|contains:
      - com.apple.WebKit.WebContent
      - firefox
      - Google Chrome Helper
      - Google Chrome
      - Microsoft Edge
      - Opera
      - Safari
      - Tor Browser
    Image|endswith:
      - /bash
      - /curl
      - /dash
      - /ksh
      - /osascript
      - /perl
      - /php
      - /pwsh
      - /python
      - /sh
      - /tcsh
      - /wget
      - /zsh
  filter_main_generic:
    CommandLine|contains: --defaults-torrc
  filter_main_ms_autoupdate:
    CommandLine|contains: /Library/Application Support/Microsoft/MAU*/Microsoft AutoUpdate.app/Contents/MacOS/msupdate
  filter_main_chrome:
    ParentImage|contains:
      - Google Chrome Helper
      - Google Chrome
    CommandLine|contains:
      - /Volumes/Google Chrome/Google Chrome.app/Contents/Frameworks/*/Resources/install.sh
      - /Applications/Google Chrome.app/Contents/Frameworks/Google Chrome Framework.framework/*/Resources/keystone_promote_preflight.sh
      - /Applications/Google Chrome.app/Contents/Frameworks/Google Chrome Framework.framework/*/Resources/keystone_promote_postflight.sh
  filter_main_ms_edge:
    ParentImage|contains: Microsoft Edge
    CommandLine|contains:
      - IOPlatformExpertDevice
      - hw.model
  filter_main_chromerecovery:
    ParentImage|contains:
      - Google Chrome Helper
      - Google Chrome
    CommandLine|contains|all:
      - /Users/
      - /Library/Application Support/Google/Chrome/recovery/
      - /ChromeRecovery
  filter_optional_null:
    CommandLine: null
  filter_optional_empty:
    CommandLine: ""
  condition: selection and not 1 of filter_main_* and not 1 of filter_optional_*
falsepositives:
  - Legitimate browser install, update and recovery scripts
level: medium
license: DRL-1.1
related:
  - id: 0250638a-2b28-4541-86fc-ea4c558fa0c6
    type: derived

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