Suspicious AWS ECR Container Upload by Unknown User

This detection identifies unusual activity related to AWS Elastic Container Registry (ECR). Specifically, it focuses on container image uploads performed by users or roles that do not typically execute such actions. This activity might indicate a compromised AWS account, a malicious insider, or the use of stolen credentials. While the provided source material lacks specific details on observed campaigns or threat actors, detecting anomalous ECR upload behavior is crucial for maintaining the integrity of containerized applications and preventing the deployment of malicious images. The alert helps defenders identify deviations from the established baseline of ECR usage within their AWS environment.

Attack Chain

Given the limited information, a generic attack chain is constructed based on the potential exploitation of this type of event:

1. Initial Access: An attacker gains unauthorized access to an AWS account, potentially through compromised credentials or exploiting a misconfigured IAM role.
2. Privilege Escalation (Optional): The attacker may attempt to elevate privileges within the AWS environment to gain broader control over resources.
3. ECR Access: The attacker gains access to the AWS ECR service, potentially using the compromised credentials or a role with sufficient permissions.
4. Image Modification/Upload: The attacker uploads a malicious container image to an existing ECR repository, replacing or adding to the available images.
5. Deployment Manipulation: The attacker modifies deployment configurations (e.g., Kubernetes manifests, ECS task definitions) to utilize the newly uploaded malicious image.
6. Execution: The malicious container image is deployed and executed within the environment, leading to further compromise or data exfiltration.
7. Persistence: The attacker may establish persistence within the compromised environment by maintaining access to the AWS account or through other means.

Impact

Successful exploitation could lead to the deployment of compromised applications within the AWS environment. This could result in data breaches, system compromise, or disruption of services. The number of potential victims depends on the scope of the compromised AWS account and the applications deployed using the affected container images. The targeted sectors are highly variable but could include any organization utilizing AWS ECR for containerized application deployment. The financial and reputational damage could be significant, especially if sensitive data is exposed or services are disrupted.