---
title: Unusual Process Extension
description: Identifies processes running with unusual extensions that are not typically valid for Windows executables. Rule type: eql Rule indices: logs-endpoint.events.process-*...
url: https://www.elastic.co/docs/reference/security/prebuilt-rules/rules_building_block/defense_evasion_unusual_process_extension
products:
  - Elastic Security
---

# Unusual Process Extension
Identifies processes running with unusual extensions that are not typically valid for Windows executables.
**Rule type**: eql
**Rule indices**:
- logs-endpoint.events.process-*

**Rule Severity**: low
**Risk Score**: 21
**Runs every**: 60m
**Searches indices from**: `now-119m`
**Maximum alerts per execution**: 100
**References**:
**Tags**:
- Domain: Endpoint
- OS: Windows
- Use Case: Threat Detection
- Tactic: Defense Evasion
- Data Source: Elastic Defend
- Rule Type: BBR
- Rule Type: Event Correlation (EQL)
- Platform: Windows

**Version**: 7
**Rule authors**:
- Elastic

**Rule license**: Elastic License v2

## Rule Query

```eql
process where host.os.type == "windows" and event.type == "start" and
  process.executable : "?*" and 
  not process.name : ("*.exe", "*.com", "*.scr", "*.tmp", "*.dat") and
  not process.executable : 
    (
      "MemCompression",
      "Registry",
      "vmmem",
      "vmmemWSL",
      "?:\\Program Files\\Dell\\SupportAssistAgent\\*.p5x",
      "?:\\Program Files\\Docker\\Docker\\com.docker.service",
      "?:\\Users\\*\\AppData\\Local\\Intel\\AGS\\Libs\\AGSRunner.bin",
      "\\Device\\Mup\\*\\Software Management\\Select.Html.dep",
      "?:\\ProgramData\\Software Management\\Select.Html.dep",
      "?:\\Program Files (x86)\\EnCase Applications\\Examiner Service\\EnCase64\\enhkey.dll",
      "?:\\Program Files (x86)\\Panda Security\\WAC\\PSNAEInj64.dll",
      "?:\\Program Files (x86)\\Johnson Controls\\LicenseActivator\\crp32002.ngn"
    ) and
  not (
    (process.name : "C9632CF058AE4321B6B0B5EA39B710FE" and process.code_signature.subject_name == "Dell Inc") or
    (process.name : "*.upd" and process.code_signature.subject_name == "Bloomberg LP") or
    (process.name: "FD552E21-686E-413C-931D-3B82A9D29F3B" and process.code_signature.subject_name: "Adobe Inc.") or
    (process.name: "3B91051C-AE82-43C9-BCEF-0309CD2DD9EB" and process.code_signature.subject_name: "McAfee, LLC") or
    (process.name: "soffice.bin" and process.code_signature.subject_name: "The Document Foundation") or
    (process.name: ("VeeamVixProxy_*", "{????????-????-????-????-????????????}") and process.code_signature.subject_name: "Veeam Software Group GmbH") or
    (process.name: "1cv8p64.bin" and process.code_signature.subject_name: "LLC 1C-Soft") or
    (process.name: "AGSRunner.bin" and process.code_signature.subject_name: "Intel Corporation")
  )
```

**Framework:** MITRE ATT&CK
- Tactic:
  - Name: Defense Evasion
  - Id: TA0005
  - Reference URL: [[https://attack.mitre.org/tactics/TA0005/](https://attack.mitre.org/tactics/TA0005/)](https://attack.mitre.org/tactics/TA0005/)
- Technique:
  - Name: Masquerading
  - Id: T1036
  - Reference URL: [[https://attack.mitre.org/techniques/T1036/](https://attack.mitre.org/techniques/T1036/)](https://attack.mitre.org/techniques/T1036/)
- Sub Technique:
  - Name: Masquerade File Type
  - Id: T1036.008
  - Reference URL: [[https://attack.mitre.org/techniques/T1036/008/](https://attack.mitre.org/techniques/T1036/008/)](https://attack.mitre.org/techniques/T1036/008/)