Detection rules › Sigma

Execution From Webserver Root Folder

Status
test
Severity
medium
Log source
product windows, category process_creation
Author
Florian Roth (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects a program executing from a web server root folder. Use this rule to hunt for potential interesting activity such as webshell or backdoors

MITRE ATT&CK coverage

Event coverage

Rule body yaml

title: Execution From Webserver Root Folder
id: 35efb964-e6a5-47ad-bbcd-19661854018d
status: test
description: |
    Detects a program executing from a web server root folder. Use this rule to hunt for potential interesting activity such as webshell or backdoors
references:
    - Internal Research
author: Florian Roth (Nextron Systems)
date: 2019-01-16
modified: 2024-01-18
tags:
    - attack.persistence
    - attack.t1505.003
    - detection.threat-hunting
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|contains:
            - '\wwwroot\'
            - '\wmpub\'
            - '\htdocs\'
    filter_main_generic:
        Image|contains:
            - 'bin\'
            - '\Tools\'
            - '\SMSComponent\'
        ParentImage|endswith: '\services.exe'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Various applications
    - Tools that include ping or nslookup command invocations
level: medium

Stages and Predicates

Stage 0: condition

selection and not 1 of filter_main_*

Stage 1: selection

selection:
    Image|contains:
        - '\wwwroot\'
        - '\wmpub\'
        - '\htdocs\'

Stage 2: not filter_main_generic

filter_main_generic:
    Image|contains:
        - 'bin\'
        - '\Tools\'
        - '\SMSComponent\'
    ParentImage|endswith: '\services.exe'

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

FieldKindExcluded values
Imagematch\SMSComponent\
Imagematch\Tools\
Imagematchbin\
ParentImageends_with\services.exe

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
Imagematch
  • \htdocs\
  • \wmpub\
  • \wwwroot\