Windows: Detect Rclone command execution with exfiltration-oriented flags

Identifies likely rclone.exe exfiltration activity on Windows by matching command-line flags and rclone executable characteristics.

FreeUnreviewedSigmahighv1
title: "Windows: Detect Rclone command execution with exfiltration-oriented flags"
id: 1deb7f7f-5be8-4f11-8463-dcabf873e164
related:
  - id: a0d63692-a531-4912-ad39-4393325b2a9c
    type: obsolete
  - id: cb7286ba-f207-44ab-b9e6-760d82b84253
    type: obsolete
  - id: e37db05d-d1f9-49c8-b464-cee1a4b11638
    type: derived
status: test
description: This rule flags Windows process creation events where the command line and executable name match Rclone usage patterns commonly associated with file exfiltration. It looks for rclone.exe execution and command-line arguments that include configuration, remote targets, and transfer options such as auto-confirm, multi-thread streaming, and TLS certificate checking disabled. The detection relies on telemetry from process creation that includes the process image path/description and full command-line content.
references:
  - https://research.nccgroup.com/2021/05/27/detecting-rclone-an-effective-tool-for-exfiltration/
  - https://thedfirreport.com/2021/03/29/sodinokibi-aka-revil-ransomware
  - https://us-cert.cisa.gov/ncas/analysis-reports/ar21-126a
  - https://labs.sentinelone.com/egregor-raas-continues-the-chaos-with-cobalt-strike-and-rclone
  - https://www.splunk.com/en_us/blog/security/darkside-ransomware-splunk-threat-update-and-detections.html
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_pua_rclone_execution.yml
author: Bhabesh Raj, Sittikorn S, Aaron Greetham (@beardofbinary) - NCC Group, Huntrule Team
date: 2021-05-10
modified: 2023-03-05
tags:
  - attack.exfiltration
  - attack.t1567.002
logsource:
  product: windows
  category: process_creation
detection:
  selection_specific_options:
    CommandLine|contains|all:
      - "--config "
      - "--no-check-certificate "
      - " copy "
  selection_rclone_img:
    - Image|endswith: \rclone.exe
    - Description: Rsync for cloud storage
  selection_rclone_cli:
    CommandLine|contains:
      - pass
      - user
      - copy
      - sync
      - config
      - lsd
      - remote
      - ls
      - mega
      - pcloud
      - ftp
      - ignore-existing
      - auto-confirm
      - transfers
      - multi-thread-streams
      - "no-check-certificate "
  condition: selection_specific_options or all of selection_rclone_*
falsepositives:
  - Unknown
level: high
license: DRL-1.1

What it detects

This rule flags Windows process creation events where the command line and executable name match Rclone usage patterns commonly associated with file exfiltration. It looks for rclone.exe execution and command-line arguments that include configuration, remote targets, and transfer options such as auto-confirm, multi-thread streaming, and TLS certificate checking disabled. The detection relies on telemetry from process creation that includes the process image path/description and full command-line content.

Known false positives

  • Unknown

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.