Detection: AWS ECR Container Scanning Findings Low Informational Unknown

Updated Date: 2024-09-30 ID: cbc95e44-7c22-443f-88fd-0424478f5589 Author: Patrick Bareiss, Eric McGinnis Splunk Type: Anomaly Product: Splunk Enterprise Security

Description

The following analytic identifies low, informational, or unknown severity findings from AWS Elastic Container Registry (ECR) image scans. It leverages AWS CloudTrail logs, specifically the DescribeImageScanFindings event, to detect these findings. This activity is significant for a SOC as it helps in early identification of potential vulnerabilities or misconfigurations in container images, which could be exploited if left unaddressed. If confirmed malicious, these findings could lead to unauthorized access, data breaches, or further exploitation within the containerized environment.

 1`cloudtrail` eventSource=ecr.amazonaws.com eventName=DescribeImageScanFindings 
 2| spath path=responseElements.imageScanFindings.findings{} output=findings 
 3| mvexpand findings 
 4| spath input=findings
 5| search severity IN ("LOW", "INFORMATIONAL", "UNKNOWN") 
 6| rename name as finding_name, description as finding_description, requestParameters.imageId.imageDigest as imageDigest, requestParameters.repositoryName as repository, userIdentity.principalId as user 
 7| eval finding = finding_name.", ".finding_description 
 8| eval phase="release" 
 9| eval severity="low" 
10| stats min(_time) as firstTime max(_time) as lastTime by awsRegion, eventName, eventSource, imageDigest, repository, user, src_ip, finding, phase, severity 
11| `security_content_ctime(firstTime)` 
12| `security_content_ctime(lastTime)` 
13| `aws_ecr_container_scanning_findings_low_informational_unknown_filter`

Data Source

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

Macros Used

Name Value
cloudtrail sourcetype=aws:cloudtrail
aws_ecr_container_scanning_findings_low_informational_unknown_filter search *
aws_ecr_container_scanning_findings_low_informational_unknown_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK
+ Kill Chain Phases
+ NIST
+ CIS
- Threat Actors
ID Technique Tactic
T1204.003 Malicious Image Execution
T1204 User Execution Execution
KillChainPhase.INSTALLATION
NistCategory.DE_AE
Cis18Value.CIS_13
TeamTNT
LAPSUS$
Scattered Spider

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
This configuration file applies to all detections of type anomaly. These detections will use Risk Based Alerting.

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
Vulnerabilities with severity $severity$ found in repository $repository$ 5 10 50
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

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: 4