ID | Technique | Tactic |
---|---|---|
T1078.004 | Cloud Accounts | Defense Evasion |
Detection: Detect AWS API Activities From Unapproved Accounts
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 successful AWS CloudTrail activity by user accounts that are not listed in the identity table or aws_service_accounts.csv
. It returns event names and count, as well as the first and last time a specific user or service is detected, grouped by users. Deprecated because managing this list can be quite hard.
Search
1`cloudtrail` errorCode=success
2| rename userName as identity
3| search NOT [
4| inputlookup identity_lookup_expanded
5| fields identity]
6| search NOT [
7| inputlookup aws_service_accounts
8| fields identity]
9| rename identity as user
10| stats count min(_time) as firstTime max(_time) as lastTime values(eventName) as eventName by user
11| `security_content_ctime(firstTime)`
12| `security_content_ctime(lastTime)`
13| `detect_aws_api_activities_from_unapproved_accounts_filter`
Data Source
Name | Platform | Sourcetype | Source | Supported App |
---|---|---|---|---|
N/A | N/A | N/A | N/A | N/A |
Macros Used
Name | Value |
---|---|
cloudtrail | sourcetype=aws:cloudtrail |
detect_aws_api_activities_from_unapproved_accounts_filter | search * |
detect_aws_api_activities_from_unapproved_accounts_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 | False |
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. You must also populate the identity_lookup_expanded
lookup shipped with the Asset and Identity framework to be able to look up users in your identity table in Enterprise Security (ES). Leverage the support search called "Create a list of approved AWS service accounts": run it once every 30 days to create and validate a list of service accounts.
This search produces fields (eventName
,firstTime
,lastTime
) that are not yet supported by ES Incident Review and therefore cannot be viewed when a notable event is raised. These fields contribute additional context to the notable. To see the additional metadata, add the following fields, if not already present, to Incident Review - Event Attributes (Configure > Incident Management > Incident Review Settings > Add New Entry):
- Label: AWS Event Name, Field: eventName
- Label: First Time, Field: firstTime
- Label: Last Time, Field: lastTime
Detailed documentation on how to create a new field within Incident Review may be found here:
https://docs.splunk.com/Documentation/ES/5.3.0/Admin/Customizenotables#Add_a_field_to_the_notable_event_details
Known False Positives
It's likely that you'll find activity detected by users/service accounts that are not listed in the identity_lookup_expanded
or aws_service_accounts.csv
file. If the user is a legitimate service account, update the aws_service_accounts.csv
table with that entry.
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: 3