---
title: "Linux Sudoers Tmp File Creation"
excerpt: "Sudo and Sudo Caching
, Abuse Elevation Control Mechanism
"
categories:
  - Endpoint
last_modified_at: 2021-12-23
toc: true
toc_label: ""
tags:
  - Sudo and Sudo Caching
  - Abuse Elevation Control Mechanism
  - Defense Evasion
  - Privilege Escalation
  - Defense Evasion
  - Privilege Escalation
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  - Endpoint
---



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#### Description

This analytic is to looks for file creation of sudoers.tmp file cause by editing /etc/sudoers using visudo or editor in linux platform. This technique may abuse by adversaries, malware author and red teamers to gain elevated privilege to targeted or compromised host. /etc/sudoers file controls who can run what commands as what users on what machines and can also control special things such as whether you need a password for particular commands. The file is composed of aliases (basically variables) and user specifications (which control who can run what).

- **Type**: [Anomaly](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**: 2021-12-23
- **Author**: Teoderick Contreras, Splunk
- **ID**: be254a5c-63e7-11ec-89da-acde48001122


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

| ID             | Technique        |  Tactic             |
| -------------- | ---------------- |-------------------- |
| [T1548.003](https://attack.mitre.org/techniques/T1548/003/) | Sudo and Sudo Caching | Defense Evasion, Privilege Escalation |

| [T1548](https://attack.mitre.org/techniques/T1548/) | Abuse Elevation Control Mechanism | Defense Evasion, Privilege Escalation |

#### Search

```

| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Filesystem where Filesystem.file_path IN ("*sudoers.tmp*") by Filesystem.dest Filesystem.file_name Filesystem.process_guid Filesystem.file_path 
| `drop_dm_object_name(Filesystem)` 
| `security_content_ctime(lastTime)` 
| `security_content_ctime(firstTime)` 
| `linux_sudoers_tmp_file_creation_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 `linux_sudoers_tmp_file_creation_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
* Filesystem.dest
* Filesystem.file_create_time
* Filesystem.file_name
* Filesystem.process_guid
* Filesystem.file_path


#### How To Implement
To successfully implement this search, you need to be ingesting logs with the process name, parent process, and command-line executions from your endpoints. If you are using Sysmon, you can use the Add-on for Linux Sysmon from Splunkbase.

#### Known False Positives
administrator or network operator can execute this command. Please update the filter macros to remove false positives.

#### Associated Analytic story
* [Linux Privilege Escalation](/stories/linux_privilege_escalation)
* [Linux Persistence Techniques](/stories/linux_persistence_techniques)


#### Kill Chain Phase
* Exploitation



#### RBA

| Risk Score  | Impact      | Confidence   | Message      |
| ----------- | ----------- |--------------|--------------|
| 72.0 | 80 | 90 | A file $file_name$ is created in $file_path$ on $dest$ |




#### Reference

* [https://forum.ubuntuusers.de/topic/sudo-visudo-gibt-etc-sudoers-tmp/](https://forum.ubuntuusers.de/topic/sudo-visudo-gibt-etc-sudoers-tmp/)



#### 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/T1548.003/sudoers_temp/sysmon_linux.log](https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1548.003/sudoers_temp/sysmon_linux.log)



[*source*](https://github.com/splunk/security_content/tree/develop/detections/endpoint/linux_sudoers_tmp_file_creation.yml) \| *version*: **1**