Windows: Rorschach execution indicator via critical command-line pattern

Windows process creation events with certain system utilities and a "11111111" command-line marker are flagged as ransomware execution activity.

FreeReviewedSigma · Critical · v5

Product: windows
Category: process_creation
Author: X__Junior (Nextron Systems) (SigmaHQ), DRL 1.1
Published: 2023-04-04
Updated: 2026-07-31

Analysis Detection

ATT&CK techniques

Execution

Recon
Resource Dev
Initial Access
Execution
- T1059.001PowerShell
- T1059.003Windows Command Shell
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule flags Windows process executions where the executable name matches specific system utilities and the command line contains the value "11111111". Such behavior is consistent with ransomware-style attempts to manipulate or disable host services and recovery mechanisms. Detection relies on Windows process creation telemetry including the image path and full command line arguments.

Reporting behind it

Related detections9 linkedT1059.001 — drag to rearrange

MSSQL Server Process Spawning Command Shell via xp_cmdshell

Suspicious MSSQL xp_cmdshell OS Command Execution via sqlservr.exe (via process_creation)

Malicious Fire Ant Host-to-Guest Command Execution via VMware Tools (via process_creation)

Malicious Office Application Spawning a Command Shell or Script Interpreter (via process_creation)

Malicious PowerShell or Command Shell Spawned by SQL Server via xp_cmdshell

Windows AppLocker Audit-Mode Events Indicate Files Would Have Been Blocked

Windows Process Creation: CrushFTP spawning PowerShell, CMD, and scripting tool execution

Windows: Suspicious child processes spawned by CrushFTP service

Windows Process Chain Involving Notepad++ Launched via RDPInit and Executed Through CMD

Windows: Rorschach execution indicator via critical command-line pattern

Pivot detection · T1059.001 · 9 related

Changelog

v5
Candidate ingested via manual entry.2026-07-31
v4
Candidate ingested via manual entry.2026-07-31
v3
Candidate ingested via manual entry.2026-07-31
v2
Candidate ingested via manual entry.2026-07-31
v1
No changelog recorded for this version.2026-07-30

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

rorschach-ransomware-execution-behavior-on-windows-via-command-line-indicators-0e9e6c63

title: "Windows: Rorschach execution indicator via critical command-line pattern"
id: 064274b9-95e1-42e9-a5cb-f2b66a2d333d
status: test
description: This rule flags Windows process executions where the executable name matches specific system utilities and the command line contains the value "11111111". Such behavior is consistent with ransomware-style attempts to manipulate or disable host services and recovery mechanisms. Detection relies on Windows process creation telemetry including the image path and full command line arguments.
references:
  - https://research.checkpoint.com/2023/rorschach-a-new-sophisticated-and-fast-ransomware/
  - https://github.com/SigmaHQ/sigma/blob/master/rules-emerging-threats/2023/Malware/Rorschach/proc_creation_win_malware_rorschach_ransomware_activity.yml
author: X__Junior (Nextron Systems), Huntrule Team
date: 2023-04-04
modified: 2023-04-22
tags:
  - attack.execution
  - attack.t1059.003
  - attack.t1059.001
  - detection.emerging-threats
logsource:
  category: process_creation
  product: windows
detection:
  selection:
    Image|endswith:
      - \bcdedit.exe
      - \net.exe
      - \net1.exe
      - \netsh.exe
      - \wevtutil.exe
      - \vssadmin.exe
    CommandLine|contains: "11111111"
  condition: selection
falsepositives:
  - Unlikely
level: critical
license: DRL-1.1
related:
  - id: 0e9e6c63-1350-48c4-9fa1-7ccb235edc68
    type: derived

Convert

This rule as a query you can run. Uses no unlock credit.

SplunkSPL