ID | Technique | Tactic |
---|---|---|
T1204.003 | Malicious Image | Execution |
T1204 | User Execution | Execution |
Detection: AWS ECR Container Upload Unknown User
Description
The following analytic detects the upload of a new container image to AWS Elastic Container Registry (ECR) by an unknown user. It leverages AWS CloudTrail logs to identify PutImage
events from the ECR service, filtering out known users. This activity is significant because container uploads should typically be performed by a limited set of authorized users. If confirmed malicious, this could indicate unauthorized access, potentially leading to the deployment of malicious containers, data exfiltration, or further compromise of the AWS environment.
Search
1`cloudtrail` eventSource=ecr.amazonaws.com eventName=PutImage NOT `aws_ecr_users`
2| rename requestParameters.* as *
3| rename repositoryName AS image
4| eval phase="release"
5| eval severity="high"
6| stats min(_time) as firstTime max(_time) as lastTime by awsRegion, eventName, eventSource, user, userName, src_ip, imageTag, registryId, image, phase, severity
7| `security_content_ctime(firstTime)`
8| `security_content_ctime(lastTime)`
9| `aws_ecr_container_upload_unknown_user_filter`
Data Source
Name | Platform | Sourcetype | Source | Supported App |
---|---|---|---|---|
AWS CloudTrail PutImage | AWS | 'aws:cloudtrail' |
'aws_cloudtrail' |
N/A |
Macros Used
Name | Value |
---|---|
aws_ecr_users | userName IN (user) |
aws_ecr_container_upload_unknown_user_filter | search * |
aws_ecr_container_upload_unknown_user_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 splunk AWS add on and Splunk App for AWS. This search works with AWS CloudTrail logs.
Known False Positives
unknown
Associated Analytic Story
Risk Based Analytics (RBA)
Risk Message | Risk Score | Impact | Confidence |
---|---|---|---|
Container uploaded from unknown user $user$ | 49 | 70 | 70 |
References
Detection Testing
Test Type | Status | Dataset | Source | Sourcetype |
---|---|---|---|---|
Validation | ✅ Passing | N/A | N/A | N/A |
Unit | ✅ Passing | Dataset | aws_cloudtrail |
aws:cloudtrail |
Integration | ✅ Passing | Dataset | aws_cloudtrail |
aws:cloudtrail |
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: 2