sigmahighHunting

Chopper Webshell Process Pattern

Detects patterns found in process executions cause by China Chopper like tiny (ASPX) webshells

MITRE ATT&CK

persistencediscovery

Detection Query

selection_origin:
  - Image|endswith: \w3wp.exe
  - ParentImage|endswith: \w3wp.exe
selection_cmdline:
  CommandLine|contains:
    - "&ipconfig&echo"
    - "&quser&echo"
    - "&whoami&echo"
    - "&c:&echo"
    - "&cd&echo"
    - "&dir&echo"
    - "&echo [E]"
    - "&echo [S]"
condition: all of selection_*

Author

Florian Roth (Nextron Systems), MSTI (query)

Created

2022-10-01

Data Sources

windowsProcess Creation Events

Platforms

windows

References

https://www.microsoft.com/security/blog/2022/09/30/analyzing-attacks-using-the-exchange-vulnerabilities-cve-2022-41040-and-cve-2022-41082/

Tags

attack.persistenceattack.discoveryattack.t1505.003attack.t1018attack.t1033attack.t1087

Raw Content

title: Chopper Webshell Process Pattern
id: fa3c117a-bc0d-416e-a31b-0c0e80653efb
status: test
description: Detects patterns found in process executions cause by China Chopper like tiny (ASPX) webshells
references:
    - https://www.microsoft.com/security/blog/2022/09/30/analyzing-attacks-using-the-exchange-vulnerabilities-cve-2022-41040-and-cve-2022-41082/
author: Florian Roth (Nextron Systems), MSTI (query)
date: 2022-10-01
tags:
    - attack.persistence
    - attack.discovery
    - attack.t1505.003
    - attack.t1018
    - attack.t1033
    - attack.t1087
logsource:
    category: process_creation
    product: windows
detection:
    selection_origin:
        - Image|endswith: '\w3wp.exe'
        - ParentImage|endswith: '\w3wp.exe'
    selection_cmdline:
        CommandLine|contains:
            - '&ipconfig&echo'
            - '&quser&echo'
            - '&whoami&echo'
            - '&c:&echo'
            - '&cd&echo'
            - '&dir&echo'
            - '&echo [E]'
            - '&echo [S]'
    condition: all of selection_*
falsepositives:
    - Unknown
level: high