Detection: Cloud Provisioning Activity From Previously Unseen City

Description

The following analytic detects cloud provisioning activities originating from previously unseen cities. It leverages cloud infrastructure logs and compares the geographic location of the source IP address against a baseline of known locations. This activity is significant as it may indicate unauthorized access or misuse of cloud resources from an unexpected location. If confirmed malicious, this could lead to unauthorized resource creation, potential data exfiltration, or further compromise of cloud infrastructure.

Search

 1
 2| tstats earliest(_time) as firstTime, latest(_time) as lastTime from datamodel=Change where (All_Changes.action=started OR All_Changes.action=created) All_Changes.status=success by All_Changes.src, All_Changes.user, All_Changes.object, All_Changes.command 
 3| `drop_dm_object_name("All_Changes")` 
 4| iplocation src 
 5| where isnotnull(City) 
 6| lookup previously_seen_cloud_provisioning_activity_sources City as City OUTPUT firstTimeSeen, enough_data 
 7| eventstats max(enough_data) as enough_data 
 8| where enough_data=1 
 9| eval firstTimeSeenCity=min(firstTimeSeen) 
10| where isnull(firstTimeSeenCity) OR firstTimeSeenCity > relative_time(now(), `previously_unseen_cloud_provisioning_activity_window`) 
11| `security_content_ctime(firstTime)` 
12| table firstTime, src, City, user, object, command 
13| `cloud_provisioning_activity_from_previously_unseen_city_filter`

Data Source

Name	Platform	Sourcetype	Source
AWS CloudTrail	AWS	'aws:cloudtrail'	'aws_cloudtrail'

Macros Used

Annotations

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Implementation

You must be ingesting your cloud infrastructure logs from your cloud provider. You should run the baseline search Previously Seen Cloud Provisioning Activity Sources - Initial to build the initial table of source IP address, geographic locations, and times. You must also enable the second baseline search Previously Seen Cloud Provisioning Activity Sources - Update to keep this table up to date and to age out old data. You can adjust the time window for this search by updating the previously_unseen_cloud_provisioning_activity_window macro. You can also provide additional filtering for this search by customizing the cloud_provisioning_activity_from_previously_unseen_city_filter macro.

Known False Positives

This is a strictly behavioral search, so we define "false positive" slightly differently. Every time this fires, it will accurately reflect the first occurrence in the time period you're searching within, plus what is stored in the cache feature. But while there are really no "false positives" in a traditional sense, there is definitely lots of noise. This search will fire any time a new IP address is seen in the GeoIP database for any kind of provisioning activity. If you typically do all provisioning from tools inside of your country, there should be few false positives. If you are located in countries where the free version of MaxMind GeoIP that ships by default with Splunk has weak resolution (particularly small countries in less economically powerful regions), this may be much less valuable to you.

Associated Analytic Story

• Suspicious Cloud Provisioning Activities

Risk Based Analytics (RBA)

Detection Testing

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: GitHub | Version: 3