Detection: AWS ECR Container Scanning Findings Medium

Updated Date: 2024-05-06 ID: 0b80e2c8-c746-4ddb-89eb-9efd892220cf Author: Patrick Bareiss, Splunk Type: Anomaly Product: Splunk Enterprise Security

Description

The following analytic identifies medium-severity findings from AWS Elastic Container Registry (ECR) image scans. It leverages AWS CloudTrail logs, specifically the DescribeImageScanFindings event, to detect vulnerabilities in container images. This activity is significant for a SOC as it highlights potential security risks in containerized applications, which could be exploited if not addressed. If confirmed malicious, these vulnerabilities could lead to unauthorized access, data breaches, or further exploitation within the container environment, compromising the overall security posture.

Search

 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=MEDIUM 
 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="medium" 
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_medium_filter`

Data Source

Name	Platform	Sourcetype	Source	Supported App
AWS CloudTrail DescribeImageScanFindings	AWS	`'aws:cloudtrail'`	`'aws_cloudtrail'`	N/A

Macros Used

Name	Value
cloudtrail	`sourcetype=aws:cloudtrail`
aws_ecr_container_scanning_findings_medium_filter	`search *`

aws_ecr_container_scanning_findings_medium_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

Dev Sec Ops

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
Vulnerabilities with severity $severity$ found in repository $repository$	21	30	70

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

https://docs.aws.amazon.com/AmazonECR/latest/userguide/image-scanning.html

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: 3