Windows Process Creation: Detects Command-Line Ending With '.exe Platypus'
Alerts when a Windows process command line ends with '.exe Platypus', matching a Small Sieve indicator.
- Product
- windows
- Category
- process_creation
- Author
- Nasreddine Bencherchali (Nextron Systems) (SigmaHQ), DRL 1.1
- Published
- 2023-05-19
- Updated
- 2026-07-31
ATT&CK techniques
Execution → Defense EvasionRecon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact
What it detects
This rule flags Windows process creation events where the command line ends with the pattern '.exe Platypus'. Attackers may use crafted command-line arguments to execute or steer malicious components, so exact command-line matching can help surface suspicious execution. It relies on process creation telemetry that includes the full command line string for running processes.
Reporting behind it
Changelog
v5- v5Candidate ingested via manual entry.2026-07-31
- v4Candidate ingested via manual entry.2026-07-31
- v3Candidate ingested via manual entry.2026-07-31
- v2Candidate ingested via manual entry.2026-07-31
- v1No 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.
title: "Windows Process Creation: Detects Command-Line Ending With '.exe Platypus'"
id: 9b8b7c97-7487-4099-b353-aaa8c5ecffad
status: test
description: This rule flags Windows process creation events where the command line ends with the pattern '.exe Platypus'. Attackers may use crafted command-line arguments to execute or steer malicious components, so exact command-line matching can help surface suspicious execution. It relies on process creation telemetry that includes the full command line string for running processes.
references:
- https://www.ncsc.gov.uk/static-assets/documents/malware-analysis-reports/small-sieve/NCSC-MAR-Small-Sieve.pdf
- https://github.com/SigmaHQ/sigma/blob/master/rules-emerging-threats/2021/Malware/Small-Sieve/proc_creation_win_malware_small_sieve_cli_arg.yml
author: Nasreddine Bencherchali (Nextron Systems), Huntrule Team
date: 2023-05-19
tags:
- attack.privilege-escalation
- attack.persistence
- attack.execution
- attack.stealth
- attack.t1574.001
- detection.emerging-threats
logsource:
product: windows
category: process_creation
detection:
selection:
CommandLine|endswith: .exe Platypus
condition: selection
falsepositives:
- Unlikely
level: high
license: DRL-1.1
related:
- id: 21117127-21c8-437a-ae03-4b51e5a8a088
type: derived