Name:AWS ECR Container Upload Unknown User id:300688e4-365c-4486-a065-7c884462b31d version:3 date:2024-09-30 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) 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. Data_source:
-AWS CloudTrail PutImage
search:`cloudtrail` eventSource=ecr.amazonaws.com eventName=PutImage NOT `aws_ecr_users` | rename requestParameters.* as * | rename repositoryName AS image | eval phase="release" | eval severity="high" | stats min(_time) as firstTime max(_time) as lastTime by awsRegion, eventName, eventSource, user, userName, src_ip, imageTag, registryId, image, phase, severity | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `aws_ecr_container_upload_unknown_user_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:unknown References: -https://attack.mitre.org/techniques/T1204/003/ drilldown_searches: name:'View the detection results for - "$user$"' search:'%original_detection_search% | search user = "$user$"' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' name:'View risk events for the last 7 days for - "$user$"' search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$") starthoursago=168 | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' tags: analytic_story: - 'Dev Sec Ops' asset_type:AWS Account confidence:70 impact:70 message:Container uploaded from unknown user $user$ mitre_attack_id: - 'T1204.003' - 'T1204' observable: name:'src_ip' type:'IP Address' - role: - 'Attacker' name:'user' type:'User' - role: - 'Victim' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' required_fields: - 'eventSource' - 'eventName' - 'awsRegion' - 'requestParameters.imageTag' - 'requestParameters.registryId' - 'requestParameters.repositoryName' - 'user' - 'userName' - 'src_ip' risk_score:49 security_domain:network
