Greedy File Deletion Using Del — Sigma Rule

Rule metadata and linked tags

Author: frack113 , X__Junior (Nextron Systems). Source status: test; severity: medium. Source dates: 2021-12-02 / 2023-09-11.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 6097997542fba37deba71e73b4ac289cc7150f50c4831a586627f01814987f8a

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: Greedy File Deletion Using Del
id: 204b17ae-4007-471b-917b-b917b315c5db
status: test
description: Detects execution of the "del" builtin command to remove files using greedy/wildcard expression. This is often used by malware to delete content of folders that perhaps contains the initial malware infection or to delete evidence.
references:
    - https://www.joesandbox.com/analysis/509330/0/html#1044F3BDBE3BB6F734E357235F4D5898582D
    - https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/erase
author: frack113 , X__Junior (Nextron Systems)
date: 2021-12-02
modified: 2023-09-11
tags:
    - attack.stealth
    - attack.t1070.004
logsource:
    category: process_creation
    product: windows
detection:
    # Example:
    #   del C:\ProgramData\*.dll & exit
    selection_img:
        - Image|endswith: '\cmd.exe'
        - OriginalFileName: 'Cmd.Exe'
    selection_del:
        CommandLine|contains:
            - 'del '
            - 'erase '
    selection_extensions:
        CommandLine|contains:
            - '\\\*.au3'
            - '\\\*.dll'
            - '\\\*.exe'
            - '\\\*.js'
    condition: all of selection_*
falsepositives:
    - Unknown
level: medium

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://www.joesandbox.com/analysis/509330/0/html#1044F3BDBE3BB6F734E357235F4D5898582D
• https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/erase