title: Shells Spawned by Web Servers
author: Thomas Patzke
date: 2019/01/16
description: Web servers that spawn shell processes could be the result of a successfully
    placed web shell or an other attack
detection:
    SELECTION_1:
        EventID: 1
    SELECTION_10:
        Image: '*\bash.exe'
    SELECTION_11:
        Image: '*\powershell.exe'
    SELECTION_12:
        Image: '*\bitsadmin.exe'
    SELECTION_2:
        ParentImage: '*\w3wp.exe'
    SELECTION_3:
        ParentImage: '*\httpd.exe'
    SELECTION_4:
        ParentImage: '*\nginx.exe'
    SELECTION_5:
        ParentImage: '*\php-cgi.exe'
    SELECTION_6:
        ParentImage: '*\tomcat.exe'
    SELECTION_7:
        ParentImage: '*\UMWorkerProcess.exe'
    SELECTION_8:
        Image: '*\cmd.exe'
    SELECTION_9:
        Image: '*\sh.exe'
    condition: (SELECTION_1 and (SELECTION_2 or SELECTION_3 or SELECTION_4 or SELECTION_5
        or SELECTION_6 or SELECTION_7) and (SELECTION_8 or SELECTION_9 or SELECTION_10
        or SELECTION_11 or SELECTION_12))
falsepositives:
- Particular web applications may spawn a shell process legitimately
fields:
- CommandLine
- ParentCommandLine
id: 8202070f-edeb-4d31-a010-a26c72ac5600
level: high
logsource:
    category: process_creation
    product: windows
modified: 2020/03/25
status: experimental
tags:
- attack.persistence
- attack.t1505.003
- attack.privilege_escalation
- attack.t1190
yml_filename: win_webshell_spawn.yml
yml_path: /Users/user/Documents/YamatoSecurity/sigma/rules/windows/process_creation