---
title: "Linux Possible Append Command To Profile Config File"
excerpt: "Unix Shell Configuration Modification, Event Triggered Execution"
categories:
  - Endpoint
last_modified_at: 2021-12-20
toc: true
toc_label: ""
tags:
  - Unix Shell Configuration Modification
  - Privilege Escalation
  - Persistence
  - Event Triggered Execution
  - Privilege Escalation
  - Persistence
  - 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 analytic looks for suspicious command-lines that can be possibly used to modify user profile files to automatically execute scripts/executables by shell upon reboot of the machine. This technique is commonly abused by adversaries, malware and red teamers as persistence mechanism to the targeted or compromised host. This Anomaly detection is a good indicator that someone wants to run code after reboot which can be done also by the administrator or network operator for automation purposes.

- **Type**: [Anomaly](https://github.com/splunk/security_content/wiki/Detection-Analytic-Types)
- **Product**: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- **Datamodel**: [Endpoint](https://docs.splunk.com/Documentation/CIM/latest/User/Endpoint)
- **Last Updated**: 2021-12-20
- **Author**: Teoderick Contreras, Splunk
- **ID**: 9c94732a-61af-11ec-91e3-acde48001122


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

| ID             | Technique        |  Tactic             |
| -------------- | ---------------- |-------------------- |
| [T1546.004](https://attack.mitre.org/techniques/T1546/004/) | Unix Shell Configuration Modification | Privilege Escalation, Persistence |

| [T1546](https://attack.mitre.org/techniques/T1546/) | Event Triggered Execution | Privilege Escalation, Persistence |

#### Search

```

| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.process = "*echo*" AND Processes.process IN("*~/.bashrc", "*~/.bash_profile", "*/etc/profile", "~/.bash_login", "*~/.profile", "~/.bash_logout") by Processes.dest Processes.user Processes.parent_process_name Processes.process_name Processes.process Processes.process_id Processes.parent_process_id Processes.process_guid 
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `linux_possible_append_command_to_profile_config_file_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_possible_append_command_to_profile_config_file_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.dest
* Processes.user
* Processes.parent_process_name
* Processes.process_name
* Processes.process
* Processes.process_id
* Processes.parent_process_id


#### 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 use this commandline for automation purposes. 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
* Privilege Escalation



#### RBA

| Risk Score  | Impact      | Confidence   | Message      |
| ----------- | ----------- |--------------|--------------|
| 49.0 | 70 | 70 | a commandline $process$ that may modify profile files in $dest$ |


Note that risk score is calculated base on the following formula: `(Impact * Confidence)/100`



#### Reference

* [https://unix.stackexchange.com/questions/129143/what-is-the-purpose-of-bashrc-and-how-does-it-work](https://unix.stackexchange.com/questions/129143/what-is-the-purpose-of-bashrc-and-how-does-it-work)
* [https://attack.mitre.org/techniques/T1546/004/](https://attack.mitre.org/techniques/T1546/004/)



#### 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/T1546.004/linux_init_profile/sysmon_linux.log](https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1546.004/linux_init_profile/sysmon_linux.log)



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