---
title: "Windows DotNet Binary in Non Standard Path"
excerpt: "Masquerading, Rename System Utilities, Signed Binary Proxy Execution, InstallUtil"
categories:
  - Endpoint
last_modified_at: 2022-01-19
toc: true
toc_label: ""
tags:
  - Masquerading
  - Defense Evasion
  - Rename System Utilities
  - Defense Evasion
  - Signed Binary Proxy Execution
  - Defense Evasion
  - InstallUtil
  - 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

The following analytic identifies native .net binaries within the Windows operating system that may be abused by adversaries by moving it to a new directory. The analytic identifies the .net binary by using a lookup and compares the process name and original file name (internal name). The analytic utilizes a lookup with the is_net_windows_file macro to identify the binary process name and original file name. if one or the other matches an alert will be generated. Adversaries abuse these binaries as they are native to windows and native DotNet. Note that not all SDK (post install of Windows) are captured in the lookup.

- **Type**: [TTP](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**: 2022-01-19
- **Author**: Michael Haag, Splunk
- **ID**: fddf3b56-7933-11ec-98a6-acde48001122


#### [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 |

| [T1218](https://attack.mitre.org/techniques/T1218/) | Signed Binary Proxy Execution | Defense Evasion |

| [T1218.004](https://attack.mitre.org/techniques/T1218/004/) | InstallUtil | Defense Evasion |

#### Search

```

| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes where NOT (Processes.process_path IN ("*\\Windows\\ADWS\\*","*\\Windows\\SysWOW64*", "*\\Windows\\system32*", "*\\Windows\\NetworkController\\*", "*\\Windows\\SystemApps\\*", "*\\WinSxS\\*", "*\\Windows\\Microsoft.NET\\*")) by Processes.dest Processes.user Processes.parent_process Processes.process_name Processes.process Processes.original_file_name Processes.process_path Processes.process_id Processes.parent_process_id 
| `drop_dm_object_name("Processes")` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `is_net_windows_file` 
| `windows_dotnet_binary_in_non_standard_path_filter`
```

#### Macros
The SPL above uses the following Macros:
* [is_net_windows_file](https://github.com/splunk/security_content/blob/develop/macros/is_net_windows_file.yml)
* [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 `windows_dotnet_binary_in_non_standard_path_filter` is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

#### Lookups
The SPL above uses the following Lookups:

* [is_net_windows_file](https://github.com/splunk/security_content/blob/develop/lookups/is_net_windows_file.yml) with [data](https://github.com/splunk/security_content/blob/develop/lookups/is_net_windows_file.csv)
* [is_net_windows_file](https://github.com/splunk/security_content/blob/develop/lookups/is_net_windows_file.yml) with [data](https://github.com/splunk/security_content/blob/develop/lookups/is_net_windows_file.csv)

#### Required field
* _time
* Processes.dest
* Processes.user
* Processes.parent_process_name
* Processes.parent_process
* Processes.original_file_name
* Processes.process_name
* Processes.process
* Processes.process_id
* Processes.parent_process_path
* Processes.process_path
* Processes.parent_process_id


#### How To Implement
To successfully implement this search you need to be ingesting information on process that include the name of the process responsible for the changes from your endpoints into the `Endpoint` datamodel in the `Processes` node. In addition, confirm the latest CIM App 4.20 or higher is installed and the latest TA for the endpoint product.

#### Known False Positives
False positives may be present and filtering may be required. Certain utilities will run from non-standard paths based on the third-party application in use.

#### Associated Analytic story
* [Masquerading - Rename System Utilities](/stories/masquerading_-_rename_system_utilities)
* [Unusual Processes](/stories/unusual_processes)
* [Ransomware](/stories/ransomware)
* [Signed Binary Proxy Execution InstallUtil](/stories/signed_binary_proxy_execution_installutil)
* [WhisperGate](/stories/whispergate)


#### Kill Chain Phase
* Exploitation



#### RBA

| Risk Score  | Impact      | Confidence   | Message      |
| ----------- | ----------- |--------------|--------------|
| 49.0 | 70 | 70 | An instance of $parent_process_name$ spawning $process_name$ from a non-standard path was identified on endpoint $dest$ by user $user$. |


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



#### Reference

* [https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1036.003/T1036.003.yaml](https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1036.003/T1036.003.yaml)
* [https://attack.mitre.org/techniques/T1036/003/](https://attack.mitre.org/techniques/T1036/003/)
* [https://www.microsoft.com/security/blog/2022/01/15/destructive-malware-targeting-ukrainian-organizations/](https://www.microsoft.com/security/blog/2022/01/15/destructive-malware-targeting-ukrainian-organizations/)
* [https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1218.004/T1218.004.md](https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1218.004/T1218.004.md)



#### 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/T1218.004/atomic_red_team/windows-sysmon_installutil_path.log](https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1218.004/atomic_red_team/windows-sysmon_installutil_path.log)



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