Windows: Detect Cmd.exe Redirection of Discovery Commands by Ursnif

Flags explorer-launched cmd.exe commands that use /C and redirect output to AppData local temp .bin files.

FreeReviewedSigma · High · v5
Product
windows
Category
process_creation
Author
@kostastsale (SigmaHQ), DRL 1.1
Published
2023-07-16
Updated
2026-07-31
title: "Windows: Detect Cmd.exe Redirection of Discovery Commands by Ursnif"
id: e54ffde2-83de-460b-b990-59a577b07f9e
status: test
description: This rule identifies a specific execution pattern where a cmd.exe process launched from explorer.exe runs a command containing '/C ' and redirects output to a temporary .bin file under AppData\local\temp\*.bin. Attackers commonly use command execution and output redirection during staging to capture discovery results or prepare follow-on steps. The detection relies on process creation telemetry, including parent image, command line content, and the presence of the output redirection target path.
references:
  - Internal Research
  - https://github.com/SigmaHQ/sigma/blob/master/rules-emerging-threats/2023/Malware/Ursnif/proc_creation_win_malware_ursnif_cmd_redirection.yml
author: "@kostastsale, Huntrule Team"
date: 2023-07-16
tags:
  - attack.execution
  - attack.t1059
  - detection.emerging-threats
logsource:
  category: process_creation
  product: windows
detection:
  selection:
    ParentImage|endswith: \explorer.exe
    Image|endswith: \cmd.exe
    CommandLine|contains|all:
      - "/C "
      - " >> *\\AppData\\local\\temp\\*.bin"
  condition: selection
falsepositives:
  - Unlikely
level: high
license: DRL-1.1
related:
  - id: 7aaa5739-12fc-41aa-b98b-23ec27d42bdf
    type: derived