AWS ECR Container Upload Outside Business Hours

name: AWS ECR Container Upload Outside Business Hours
id: d4c4d4eb-3994-41ca-a25e-a82d64e125bb
version: 12
creation_date: '2021-08-19'
modification_date: '2026-05-13'
author: Patrick Bareiss, Splunk
status: production
type: Anomaly
description: The following analytic detects the upload of a new container image to AWS Elastic Container Registry (ECR) outside of standard business hours. It leverages AWS CloudTrail logs to identify `PutImage` events occurring between 8 PM and 8 AM or on weekends. This activity is significant because container uploads outside business hours can indicate unauthorized or suspicious activity, potentially pointing to a compromised account or insider threat. If confirmed malicious, this could allow an attacker to deploy unauthorized or malicious containers, leading to potential data breaches or service disruptions.
data_source:
    - AWS CloudTrail PutImage
search: |-
    `cloudtrail` eventSource=ecr.amazonaws.com eventName=PutImage date_hour>=20 OR date_hour<8 OR date_wday=saturday OR date_wday=sunday
      | rename requestParameters.* as *
      | rename repositoryName AS repository
      | rename user_name as user
      | stats count min(_time) as firstTime max(_time) as lastTime
        BY signature user user_agent
           src vendor_account vendor_region
           vendor_product repository
      | `security_content_ctime(firstTime)`
      | `security_content_ctime(lastTime)`
      | `aws_ecr_container_upload_outside_business_hours_filter`
how_to_implement: You must install splunk AWS add on and Splunk App for AWS. This search works with AWS CloudTrail logs.
known_false_positives: When your development is spreaded in different time zones, applying this rule can be difficult.
references:
    - https://attack.mitre.org/techniques/T1204/003/
intermediate_findings:
    entities:
        - field: user
          type: user
          score: 20
          message: Container uploaded outside business hours from $user$
threat_objects:
    - field: src
      type: ip_address
analytic_story:
    - Dev Sec Ops
asset_type: AWS Account
mitre_attack_id:
    - T1204.003
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: cloud
security_domain: network