ID | Technique | Tactic |
---|
Detection: EC2 Instance Started With Previously Unseen Instance Type
DEPRECATED DETECTION
This detection has been marked as deprecated by the Splunk Threat Research team. This means that it will no longer be maintained or supported. If you have any questions or concerns, please reach out to us at research@splunk.com.
Description
This search looks for EC2 instances being created with previously unseen instance types. This search is deprecated and have been translated to use the latest Change Datamodel.
Search
1`cloudtrail` eventName=RunInstances [search `cloudtrail` eventName=RunInstances errorCode=success
2| fillnull value="m1.small" requestParameters.instanceType
3| stats earliest(_time) as earliest latest(_time) as latest by requestParameters.instanceType
4| rename requestParameters.instanceType as instanceType
5| inputlookup append=t previously_seen_ec2_instance_types.csv
6| stats min(earliest) as earliest max(latest) as latest by instanceType
7| outputlookup previously_seen_ec2_instance_types.csv
8| eval newType=if(earliest >= relative_time(now(), "-70m@m"), 1, 0)
9| `security_content_ctime(earliest)`
10| `security_content_ctime(latest)`
11| where newType=1
12| rename instanceType as requestParameters.instanceType
13| table requestParameters.instanceType]
14| spath output=user userIdentity.arn
15| rename requestParameters.instanceType as instanceType, responseElements.instancesSet.items{}.instanceId as dest
16| table _time, user, dest, instanceType
17| `ec2_instance_started_with_previously_unseen_instance_type_filter`
Data Source
No data sources specified for this detection.
Macros Used
Name | Value |
---|---|
cloudtrail | sourcetype=aws:cloudtrail |
ec2_instance_started_with_previously_unseen_instance_type_filter | search * |
ec2_instance_started_with_previously_unseen_instance_type_filter
is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Annotations
Default Configuration
This detection is configured by default in Splunk Enterprise Security to run with the following settings:
Setting | Value |
---|---|
Disabled | true |
Cron Schedule | 0 * * * * |
Earliest Time | -70m@m |
Latest Time | -10m@m |
Schedule Window | auto |
Creates Risk Event | True |
Implementation
You must install the AWS App for Splunk (version 5.1.0 or later) and Splunk Add-on for AWS (version 4.4.0 or later), then configure your AWS CloudTrail inputs. This search works best when you run the "Previously Seen EC2 Instance Types" support search once to create a history of previously seen instance types.
Known False Positives
It is possible that an admin will create a new system using a new instance type never used before. Verify with the creator that they intended to create the system with the new instance type.
Associated Analytic Story
Risk Based Analytics (RBA)
Risk Message | Risk Score | Impact | Confidence |
---|---|---|---|
tbd | 25 | 50 | 50 |
Detection Testing
Test Type | Status | Dataset | Source | Sourcetype |
---|---|---|---|---|
Validation | Not Applicable | N/A | N/A | N/A |
Unit | ❌ Failing | N/A | N/A |
N/A |
Integration | ❌ Failing | N/A | N/A |
N/A |
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: 4