---
title: "Execution of File with Multiple Extensions"
excerpt: "Masquerading
, Rename System Utilities
"
categories:
  - Endpoint
last_modified_at: 2020-11-18
toc: true
toc_label: ""
tags:
  - Masquerading
  - Rename System Utilities
  - Defense Evasion
  - Defense Evasion
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  - Endpoint
---



[Try in Splunk Security Cloud](https://www.splunk.com/en_us/cyber-security.html){: .btn .btn--success}

#### Description

This search looks for processes launched from files that have double extensions in the file name. This is typically done to obscure the "real" file extension and make it appear as though the file being accessed is a data file, as opposed to executable content.

- **Type**: [TTP](https://github.com/splunk/security_content/wiki/object-Analytic-Types)
- **Product**: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- **Datamodel**: [Endpoint](https://docs.splunk.com/Documentation/CIM/latest/User/Endpoint)
- **Last Updated**: 2020-11-18
- **Author**: Rico Valdez, Splunk
- **ID**: b06a555e-dce0-417d-a2eb-28a5d8d66ef7


#### [ATT&CK](https://attack.mitre.org/)

| ID             | Technique        |  Tactic             |
| -------------- | ---------------- |-------------------- |
| [T1036](https://attack.mitre.org/techniques/T1036/) | Masquerading | Defense Evasion |

| [T1036.003](https://attack.mitre.org/techniques/T1036/003/) | Rename System Utilities | Defense Evasion |

#### Search

```

| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.process = *.doc.exe OR Processes.process = *.htm.exe OR Processes.process = *.html.exe OR Processes.process = *.txt.exe OR Processes.process = *.pdf.exe OR Processes.process = *.doc.exe by Processes.dest Processes.user Processes.process Processes.parent_process 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `drop_dm_object_name(Processes)` 
| `execution_of_file_with_multiple_extensions_filter`
```

#### Macros
The SPL above uses the following Macros:
* [security_content_ctime](https://github.com/splunk/security_content/blob/develop/macros/security_content_ctime.yml)
* [security_content_summariesonly](https://github.com/splunk/security_content/blob/develop/macros/security_content_summariesonly.yml)

Note that `execution_of_file_with_multiple_extensions_filter` is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

#### Required field
* _time
* Processes.process
* Processes.dest
* Processes.user
* Processes.parent_process


#### How To Implement
To successfully implement this search, you must be ingesting data that records process activity from your hosts to populate the endpoint data model in the processes node.

#### Known False Positives
None identified.

#### Associated Analytic story
* [Windows File Extension and Association Abuse](/stories/windows_file_extension_and_association_abuse)
* [Masquerading - Rename System Utilities](/stories/masquerading_-_rename_system_utilities)


#### Kill Chain Phase
* Actions on Objectives



#### RBA

| Risk Score  | Impact      | Confidence   | Message      |
| ----------- | ----------- |--------------|--------------|
| 56.0 | 80 | 70 | process $process$ have double extensions in the file name is executed on $dest$ by $user$ |




#### Reference


#### Test Dataset
Replay any dataset to Splunk Enterprise by using our [`replay.py`](https://github.com/splunk/attack_data#using-replaypy) tool or the [UI](https://github.com/splunk/attack_data#using-ui).
Alternatively you can replay a dataset into a [Splunk Attack Range](https://github.com/splunk/attack_range#replay-dumps-into-attack-range-splunk-server)


* [https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1036.003/atomic_red_team/windows-sysmon.log](https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1036.003/atomic_red_team/windows-sysmon.log)



[*source*](https://github.com/splunk/security_content/tree/develop/detections/endpoint/execution_of_file_with_multiple_extensions.yml) \| *version*: **3**