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- Datasource: Splunk Add-on for Amazon Kinesis Firehose
- Last Updated: 2020-09-02
- Author: David Dorsey, Splunk
- ID: fa4089e2-50e3-40f7-8469-d2cc1564ca59
|T1535||Unused/Unsupported Cloud Regions||Defense Evasion|
Kill Chain Phase
- Actions on Objectives
- CIS 12
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`
The SPL above uses the following Macros:
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.
The SPL above uses the following Lookups:
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
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
|42.0||70||60||User $user$ is creating an instance $dest$ in a new region for the first time|
source | version: 1