---
title: "Cloud Compute Instance Created In Previously Unused Region"
excerpt: "Unused/Unsupported Cloud Regions"
categories:
  - Cloud
last_modified_at: 2020-09-02
toc: true
toc_label: ""
tags:
  - Unused/Unsupported Cloud Regions
  - Defense Evasion
  - Splunk Security Analytics for AWS
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  - Change
---



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#### Description

This search looks at cloud-infrastructure events where an instance is created in any region within the last hour and then compares it to a lookup file of previously seen regions where instances have been created.

- **Type**: [Anomaly](https://github.com/splunk/security_content/wiki/Detection-Analytic-Types)
- **Product**: Splunk Security Analytics for AWS, Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- **Datamodel**: [Change](https://docs.splunk.com/Documentation/CIM/latest/User/Change)
- **Last Updated**: 2020-09-02
- **Author**: David Dorsey, Splunk
- **ID**: fa4089e2-50e3-40f7-8469-d2cc1564ca59


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

| ID             | Technique        |  Tactic             |
| -------------- | ---------------- |-------------------- |
| [T1535](https://attack.mitre.org/techniques/T1535/) | Unused/Unsupported Cloud Regions | Defense Evasion |

#### Search

```

| tstats earliest(_time) as firstTime latest(_time) as lastTime values(All_Changes.object_id) as dest, count from datamodel=Change where All_Changes.action=created by All_Changes.vendor_region, All_Changes.user 
| `drop_dm_object_name("All_Changes")` 
| lookup previously_seen_cloud_regions vendor_region as vendor_region OUTPUTNEW firstTimeSeen, enough_data 
| eventstats max(enough_data) as enough_data 
| where enough_data=1 
| eval firstTimeSeenRegion=min(firstTimeSeen) 
| where isnull(firstTimeSeenRegion) OR firstTimeSeenRegion > relative_time(now(), "-24h@h") 
| table firstTime, user, dest, count , vendor_region 
| `security_content_ctime(firstTime)` 
| `cloud_compute_instance_created_in_previously_unused_region_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)

Note that `cloud_compute_instance_created_in_previously_unused_region_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:

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

#### Required field
* _time
* All_Changes.object_id
* All_Changes.action
* All_Changes.vendor_region
* All_Changes.user


#### How To Implement
You must be ingesting your cloud infrastructure logs from your cloud provider. You should run the baseline search `Previously Seen Cloud Regions - Initial` to build the initial table of images observed and times. You must also enable the second baseline search `Previously Seen Cloud Regions - Update` to keep this table up to date and to age out old data. You can also provide additional filtering for this search by customizing the `cloud_compute_instance_created_in_previously_unused_region_filter` macro.

#### Known False Positives
It&#39;s possible that a user has unknowingly started an instance in a new region. Please verify that this activity is legitimate.

#### Associated Analytic story
* [Cloud Cryptomining](/stories/cloud_cryptomining)


#### Kill Chain Phase
* Actions on Objectives



#### RBA

| Risk Score  | Impact      | Confidence   | Message      |
| ----------- | ----------- |--------------|--------------|
| 42.0 | 70 | 60 | User $user$ is creating an instance $dest$ in a new region for the first time |


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



#### 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/suspicious_behaviour/abnormally_high_cloud_instances_launched/cloudtrail_behavioural_detections.json](https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/suspicious_behaviour/abnormally_high_cloud_instances_launched/cloudtrail_behavioural_detections.json)



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