Cloud Compute Instance Created In Previously Unused Region
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
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Change
- Last Updated: 2020-09-02
- Author: David Dorsey, Splunk
- ID: fa4089e2-50e3-40f7-8469-d2cc1564ca59
Annotations
Kill Chain Phase
- Actions on Objectives
NIST
- DE.DP
- DE.AE
CIS20
- CIS 12
CVE
Search
1
2
3
4
5
6
7
8
9
10
11
| 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:
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:
Supported Add-on (TA)
List of Splunk Add-on’s tested to work with the analytic.
Required fields
List of fields required to use this analytic.
- _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's possible that a user has unknowingly started an instance in a new region. Please verify that this activity is legitimate.
Associated Analytic Story
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 |
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
Reference
Test Dataset
Replay any dataset to Splunk Enterprise by using our replay.py
tool or the UI.
Alternatively you can replay a dataset into a Splunk Attack Range
source | version: 1