File and Directory Discovery - MacOS — Sigma Rule

Rule metadata and linked tags

Author: Daniil Yugoslavskiy, oscd.community. Source status: test; severity: informational. Source dates: 2020-10-19 / 2022-11-25.

{
  "category": "process_creation",
  "product": "macos"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 3d53ad198421099f3e315ea5974aa7e5b6e32f4fdb3cf17ab9df90d85499694a

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: File and Directory Discovery - MacOS
id: 089dbdf6-b960-4bcc-90e3-ffc3480c20f6
status: test
description: Detects usage of system utilities to discover files and directories
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1083/T1083.md
author: Daniil Yugoslavskiy, oscd.community
date: 2020-10-19
modified: 2022-11-25
tags:
    - attack.discovery
    - attack.t1083
logsource:
    category: process_creation
    product: macos
detection:
    select_file_with_asterisk:
        Image: '/usr/bin/file'
        CommandLine|re: '(.){200,}' # execution of the 'file */* *>> /tmp/output.txt' will produce huge commandline
    select_recursive_ls:
        Image: '/bin/ls'
        CommandLine|contains: '-R'
    select_find_execution:
        Image: '/usr/bin/find'
    select_mdfind_execution:
        Image: '/usr/bin/mdfind'
    select_tree_execution|endswith:
        Image: '/tree'
    condition: 1 of select*
falsepositives:
    - Legitimate activities
level: informational

Original YAML and metadata in JSON

False positives

• Legitimate activities

Source references

• https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1083/T1083.md