Windows Suspicious Child Process from Node.js - React2Shell

title: Windows Suspicious Child Process from Node.js - React2Shell
id: 271de298-cc0e-4842-acd8-079a0a99ea65
related:
    - id: c70834fa-fb9d-4aa0-9e7d-45ceed36f3f7
      type: similar
status: experimental
description: |
    Detects suspicious child processes started by Node.js server processes on Windows, which may indicate exploitation of vulnerabilities like CVE-2025-55182 (React2Shell).
    Attackers can abuse the Node.js 'child_process' module to run system commands or scripts using methods such as spawn(), exec(), execFile(), fork(), or execSync().
    If execSync() or exec() is used in the exploit, the command line often shows a shell (e.g., cmd.exe /d /s /c ...) running a suspicious command unless other shells are explicitly invoked.
    For other methods, the spawned process appears directly in the Image field unless a shell is explicitly used.
references:
    - https://github.com/msanft/CVE-2025-55182
    - https://nodejs.org/api/child_process.html#class-childprocess
    - https://gist.github.com/swachchhanda000/a0228130f86a2dedfbcebb415b47f870
    - https://github.com/nasbench/Misc-Research/blob/2f651ede832ab34027a7ba005b63bb78f1ade378/Other/React-Next-Child-Processes-Notes.md
author: Swachchhanda Shrawan Poudel (Nextron Systems), Nasreddine Bencherchali
date: 2025-12-05
tags:
    - attack.execution
    - attack.t1059
    - attack.initial-access
    - attack.t1190
    - detection.emerging-threats
    - cve.2025-55182
logsource:
    category: process_creation
    product: windows
detection:
    selection_parent:
        ParentImage|endswith: '\node.exe'
        ParentCommandLine|contains:
            - '--experimental-https'
            - '--experimental-next-config-strip-types'
            - '\node_modules\next'
            - 'next dev'
            - 'next start'
            - 'next" start'
            - 'node_modules\\.bin\\\\..\\next' # We escape every backslash to avoid confusion
            - 'react-scripts start'
            - 'start-server.js'
    selection_generic_child_img:
        # Observed when child_process.spawn(), child_process.exec(), child_process.execFile(), or child_process.fork() method  is used to spawn suspicious processes
        - Image|endswith:
              - '\bash.exe'
              - '\bitsadmin.exe'
              - '\certutil.exe'
              - '\cscript.exe'
              - '\curl.exe'
              - '\ipconfig.exe'
              - '\mshta.exe'
              - '\net.exe'
              - '\net1.exe'
              - '\netsh.exe'
              - '\nslookup.exe'
              - '\OpenConsole.exe'
              - '\perl.exe'
              - '\ping.exe'
              - '\powershell.exe'
              - '\pwsh.exe'
              - '\py.exe'
              - '\python.exe'
              - '\pythonw.exe'
              - '\pyw.exe'
              - '\reg.exe'
              - '\regsvr32.exe'
              - '\rundll32.exe'
              - '\sc.exe'
              - '\sh.exe'
              - '\systeminfo.exe'
              - '\wget.exe'
              - '\whoami.exe'
              - '\wmic.exe'
              - '\wscript.exe'
              - '\wt.exe'
        - Image|contains: '\python'
    selection_generic_child_cli_susp_pattern:
        # Observed when child_process.execSync() is used to spawn suspicious processes
        # Reference: https://nodejs.org/api/child_process.html#child_processexecsynccommand-options
        # In default, the cli will look something like `C:\WINDOWS\System32\cmd.exe /d /s /c "...susp..cli...."`
        CommandLine|contains:
            - '\net'
            - 'bitsadmin'
            - 'certutil '
            - 'conhost --headless'
            - 'cscript '
            - 'curl'
            - 'ipconfig'
            - 'java'
            - 'lua'
            - 'mshta'
            - 'netsh'
            - 'nslookup '
            - 'perl'
            - 'ping '
            - 'powershell'
            - 'pwsh'
            - 'python'
            - 'reg '
            - 'reg.exe'
            - 'regsvr32'
            - 'ruby'
            - 'rundll32'
            - 'sc.exe'
            - 'systeminfo'
            - 'wget'
            - 'whoami'
            - 'wmic'
            - 'wscript'
    selection_specific_cmd:
        Image|endswith: '\cmd.exe'
    selection_specific_cli:
        CommandLine|contains: '/d /s /c '
    filter_main_default_shell_flag:
        CommandLine|contains: '/d /s /c '
    filter_main_cli_git:
        CommandLine|contains: 'git config --local --get remote.origin.url'
    filter_main_cli_netstat:
        CommandLine|contains|all:
            - 'netstat -ano | findstr /C:'
            - ' | findstr LISTENING'
    filter_main_cli_mkcert_install:
        CommandLine|contains|all:
            - '\mkcert\'
            - ' -install '
    filter_main_cli_mkcert_caroot:
        CommandLine|contains|all:
            - '\mkcert\'
            - ' -CAROOT'
    condition:
        selection_parent and
        (
            1 of selection_generic_*
            or
            (selection_specific_cmd and not filter_main_default_shell_flag)
            or
            (all of selection_specific_* and not 1 of filter_main_cli_*)
        )
falsepositives:
    - Unknown
level: high
regression_tests_path: regression_data/rules-emerging-threats/2025/Exploits/CVE-2025-55182/proc_creation_win_exploit_cve_2025_55182_susp_nodejs_server_child_process/info.yml