Sigma rule: Webshell Tool Reconnaissance Activity

Rule

Title

Webshell Tool Reconnaissance Activity

Status

test

Level

high

Author

Cian Heasley, Florian Roth (Nextron Systems)

Date

2020-07-22

Modified

2023-11-09

File

rules/windows/process_creation/proc_creation_win_webshell_tool_recon.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects processes spawned from web servers (PHP, Tomcat, IIS, etc.) that perform reconnaissance looking for the existence of popular scripting tools (perl, python, wget) on the system via the help commands

Log source

product

windows

category

process_creation

Detection

selection_webserver_image:
    ParentImage|endswith:
        - '\caddy.exe'
        - '\httpd.exe'
        - '\nginx.exe'
        - '\php-cgi.exe'
        - '\w3wp.exe'
        - '\ws_tomcatservice.exe'
selection_webserver_characteristics_tomcat1:
    ParentImage|endswith:
        - '\java.exe'
        - '\javaw.exe'
    ParentImage|contains:
        - '-tomcat-'
        - '\tomcat'
selection_webserver_characteristics_tomcat2:
    ParentImage|endswith:
        - '\java.exe'
        - '\javaw.exe'
    CommandLine|contains:
        - 'CATALINA_HOME'
        - 'catalina.jar'
selection_recon:
    CommandLine|contains:
        - 'perl --help'
        - 'perl -h'
        - 'python --help'
        - 'python -h'
        - 'python3 --help'
        - 'python3 -h'
        - 'wget --help'
condition: 1 of selection_webserver_* and selection_recon

False positives (as the rule lists them)

• Unknown

Tags

• attack.persistence
• attack.t1505.003

MITRE ATT&CK ids this rule names

• T1505.003

References

• https://ragged-lab.blogspot.com/2020/07/webshells-automating-reconnaissance.html

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_webshell_tool_recon.yml