Detection rules › Sigma

File And SubFolder Enumeration Via Dir Command

Status
test
Severity
low
Log source
product windows, category process_creation
Author
frack113
Source
github.com/SigmaHQ/sigma

Detects usage of the "dir" command part of Windows CMD with the "/S" command line flag in order to enumerate files in a specified directory and all subdirectories.

MITRE ATT&CK coverage

TacticTechniques
DiscoveryT1217 Browser Information Discovery

Event coverage

ProviderEventTitle
SysmonEvent ID 1Process creation

Rule body yaml

title: File And SubFolder Enumeration Via Dir Command
id: 7c9340a9-e2ee-4e43-94c5-c54ebbea1006
status: test
description: |
    Detects usage of the "dir" command part of Windows CMD with the "/S" command line flag in order to enumerate files in a specified directory and all subdirectories.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1217/T1217.md
author: frack113
date: 2021-12-13
modified: 2026-05-18
tags:
    - attack.discovery
    - attack.t1217
logsource:
    category: process_creation
    product: windows
detection:
    selection_cmd:
        - Image|endswith: '\cmd.exe'
        - OriginalFileName: Cmd.Exe
    selection_cli:
        CommandLine|contains|windash: '-s'
        CommandLine|contains: 'dir '
    filter_main_rmdir:
        CommandLine|contains: 'rmdir'
    condition: all of selection_* and not 1 of filter_main_*
falsepositives:
    - Likely
level: low
regression_tests_path: regression_data/rules/windows/process_creation/proc_creation_win_cmd_dir_execution/info.yml
simulation:
    - type: atomic-red-team
      name: List Internet Explorer Bookmarks using the command prompt
      technique: T1217
      atomic_guid: 727dbcdb-e495-4ab1-a6c4-80c7f77aef85

Stages and Predicates

Stage 0: condition

all of selection_* and not 1 of filter_main_*

Stage 1: selection_cmd

selection_cmd:
    - Image|endswith: '\cmd.exe'
    - OriginalFileName: Cmd.Exe

Stage 2: selection_cli

selection_cli:
    CommandLine|contains|windash: '-s'
    CommandLine|contains: 'dir '

Stage 3: not filter_main_rmdir

filter_main_rmdir:
    CommandLine|contains: 'rmdir'

Exclusions

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

FieldKindExcluded values
CommandLinematchrmdir

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
CommandLinematch
  • -s transforms: windash corpus 10 (sigma 4, kusto 4, elastic 1, splunk 1)
  • dir corpus 8 (sigma 5, splunk 2, chronicle 1)
Imageends_with
  • \cmd.exe corpus 130 (sigma 130)
OriginalFileNameeq
  • Cmd.Exe corpus 65 (sigma 43, splunk 17, elastic 5)