Windows PowerShell Script File Creation Matching FIN7-Style Filenames
Alerts on Windows PowerShell script drops named host_ip.ps1 or ending with _64refl.ps1.
FreeReviewedSigma · High · v5
- Product
- windows
- Category
- file_event
- Author
- Nasreddine Bencherchali (Nextron Systems) (SigmaHQ), DRL 1.1
- Published
- 2023-05-04
- Updated
- 2026-07-31
What it detects
Identifies creation of PowerShell script files on Windows when the target filename matches known FIN7-associated naming patterns, including files ending with “_64refl.ps1” or named “host_ip.ps1”. Attackers may stage PowerShell tooling by dropping scripts with consistent filenames to enable execution and reuse. The detection relies on Windows file creation telemetry that includes the target file path or name for new script files.
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.
windows-powershell-script-file-creation-with-64refl-ps1-or-host-ip-ps1-a88d9f45
title: Windows PowerShell Script File Creation Matching FIN7-Style Filenames
id: 8015297b-afca-49cf-84cb-8726d596fcf8
status: test
description: Identifies creation of PowerShell script files on Windows when the target filename matches known FIN7-associated naming patterns, including files ending with “_64refl.ps1” or named “host_ip.ps1”. Attackers may stage PowerShell tooling by dropping scripts with consistent filenames to enable execution and reuse. The detection relies on Windows file creation telemetry that includes the target file path or name for new script files.
references:
- https://labs.withsecure.com/publications/fin7-target-veeam-servers
- https://github.com/SigmaHQ/sigma/blob/master/rules-emerging-threats/2023/TA/FIN7/file_event_win_apt_fin7_powershell_scripts_naming_convention.yml
author: Nasreddine Bencherchali (Nextron Systems), Huntrule Team
date: 2023-05-04
tags:
- attack.execution
- attack.g0046
- detection.emerging-threats
logsource:
category: file_event
product: windows
detection:
selection:
- TargetFilename|endswith: _64refl.ps1
- TargetFilename: host_ip.ps1
condition: selection
falsepositives:
- Unknown
level: high
license: DRL-1.1
related:
- id: a88d9f45-ec8a-4b0e-85ee-c9f6a65e9128
type: derived