Renamed CURL.EXE Execution — Sigma Rule

Rule metadata and linked tags

Author: X__Junior (Nextron Systems). Source status: test; severity: medium. Source dates: 2023-09-11 / 2023-10-12.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: c95a5c5a3aa657e7e1f7d69218fa5ae111cdc9e86c09350bee5338d6d285c74b

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: Renamed CURL.EXE Execution
id: 7530cd3d-7671-43e3-b209-976966f6ea48
status: test
description: Detects the execution of a renamed "CURL.exe" binary based on the PE metadata fields
references:
    - https://twitter.com/Kostastsale/status/1700965142828290260
author: X__Junior (Nextron Systems)
date: 2023-09-11
modified: 2023-10-12
tags:
    - attack.execution
    - attack.stealth
    - attack.t1059
    - attack.t1202
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        - OriginalFileName: 'curl.exe'
        - Description: 'The curl executable'
    filter_main_img:
        Image|contains: '\curl'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Unknown
level: medium
regression_tests_path: regression_data/rules/windows/process_creation/proc_creation_win_renamed_curl/info.yml

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://twitter.com/Kostastsale/status/1700965142828290260