European Commission Hit by Data Breach; Attacker Claims 350GB Exfiltrated from AWS Cloud

European Commission Confirms Cyberattack on AWS-Hosted Cloud Infrastructure, Resulting in Data Breach

HIGH
March 28, 2026
March 30, 2026
6m read
Data BreachCloud SecurityCyberattack

Related Entities(initial)

Organizations

Amazon Web Services (AWS)European CommissionEuropean Union

Full Report(when first published)

Executive Summary

The European Commission has acknowledged a data breach impacting its cloud environment hosted on Amazon Web Services (AWS). The attack, which affected the public-facing Europa.eu websites, reportedly resulted in the exfiltration of over 350 GB of data. An unidentified attacker has claimed responsibility and stated the stolen data includes databases and employee records. The Commission asserts that its core internal systems were not compromised and that no extortion demands have been made. This incident, following a separate compromise of its mobile device management (MDM) system earlier in the year, underscores the sophisticated and persistent threats targeting high-value government institutions, even within secure cloud environments.


Threat Overview

The cyberattack specifically targeted the Commission's AWS-hosted infrastructure that supports the Europa.eu family of websites. An attacker or group has claimed to have successfully breached this environment and exfiltrated a significant volume of data, estimated at over 350 GB. The attacker's claims suggest the compromised data could include:

  • Website databases
  • Employee records
  • Other sensitive information related to the public-facing web services.

Notably, the attacker has reportedly denied any intent to extort the Commission, suggesting the motive may be hacktivism, intelligence gathering, or simply to demonstrate a capability and cause reputational damage. The Commission's quick statement that internal systems were unaffected suggests the breach was contained to a specific, likely public-facing, segment of their cloud presence. This incident highlights that even with a major cloud provider like AWS, misconfigurations or application-level vulnerabilities can lead to significant breaches.

Technical Analysis

While the specific vector is unconfirmed, a breach of this nature in an AWS environment typically stems from one of several common issues:

  • Misconfigured S3 Buckets: Publicly accessible S3 buckets containing sensitive data remain a common source of cloud breaches.
  • Compromised IAM Credentials: An attacker may have obtained AWS Identity and Access Management (IAM) keys through phishing, a leak on a public code repository, or by compromising a developer's workstation. T1078.004 - Cloud Accounts.
  • Vulnerable Web Application: A vulnerability (e.g., SQL injection, RCE) in the code of one of the Europa.eu websites could have been exploited to gain a foothold within the cloud environment. T1190 - Exploit Public-Facing Application.
  • Server-Side Request Forgery (SSRF): An SSRF flaw could have allowed the attacker to trick the web server into making requests to the internal AWS metadata service, potentially exfiltrating IAM credentials.

Once inside, the attacker would have used their access to discover and exfiltrate data from databases (e.g., RDS instances) and storage services (S3 buckets). The exfiltration of 350 GB (T1530 - Data from Cloud Storage Object) points to a significant level of access and a period of undetected activity.

Impact Assessment

  • Reputational Damage: A data breach at the executive branch of the European Union is a significant blow to public trust and confidence in the EU's ability to secure its own data.
  • Data Privacy Concerns: If employee records or other personally identifiable information (PII) were indeed exfiltrated, the Commission could face internal scrutiny and questions regarding its own adherence to GDPR principles.
  • Operational Disruption: While core systems were unaffected, the need to respond to the incident, investigate the breach, and harden the affected cloud environment requires significant resources and can disrupt normal IT operations.
  • Intelligence Value: Even if not used for extortion, the stolen databases and records could provide valuable intelligence to a nation-state actor regarding the structure, personnel, and operations of the European Commission.

Cyber Observables for Detection

Type Value Description Context Confidence
log_source AWS CloudTrail Logs Monitor for suspicious IAM activity, such as creation of new users, privilege escalation, or API calls from unusual IP ranges. AWS CloudTrail, SIEM, Cloud Security Posture Management (CSPM) tools. high
log_source S3 Access Logs Monitor for anomalous GetObject requests, especially from unexpected sources or in large volumes, which can indicate data exfiltration from S3 buckets. S3 Server Access Logging, AWS Macie. high
log_source VPC Flow Logs Analyze network traffic for large, sustained data transfers from internal cloud resources (like EC2 instances or RDS databases) to external IP addresses. VPC Flow Logs analyzed in a SIEM or Amazon Detective. high
api_endpoint http://169.254.169.254/latest/meta-data/ Monitor web server logs for requests to the EC2 metadata service, which could indicate an SSRF attack attempting to steal credentials. Web Application Firewall (WAF) logs, application server logs. medium

Detection & Response

Detecting cloud breaches requires robust monitoring of the cloud control plane and data plane.

  • Cloud Security Posture Management (CSPM): Use CSPM tools to continuously scan for misconfigurations like public S3 buckets or overly permissive IAM policies.
  • Cloud Workload Protection Platform (CWPP): Deploy CWPP agents on EC2 instances to detect malicious activity at the workload level.
  • Threat Detection Services: Leverage native AWS security services like GuardDuty (threat detection), Macie (data discovery and protection), and Detective (log analysis and investigation).
  • Response: The EU's pledge to strengthen protections indicates they are in the process of investigating the root cause, assessing the full scope of the data loss, and implementing corrective security controls in their AWS environment.

Mitigation

  • IAM Best Practices: Enforce the principle of least privilege for all IAM users and roles. Avoid using long-lived access keys; instead, use temporary credentials and IAM roles where possible. Mandate MFA for all users. Reference M1026 - Privileged Account Management.
  • Data-at-Rest Encryption: Encrypt all data stored in S3 buckets and RDS databases using AWS KMS. While this doesn't prevent exfiltration by a user with valid permissions, it's a critical layer of defense.
  • Secure Configuration: Regularly audit cloud configurations against a security baseline like the CIS AWS Foundations Benchmark.
  • Web Application Firewall (WAF): Place a WAF in front of all public-facing web applications to protect against common web exploits like SQL injection and XSS.

Timeline of Events

1
January 1, 2026
A separate security incident compromised the European Commission's mobile device management system.
2
March 28, 2026
This article was published

Article Updates

March 30, 2026

Severity increased

Notorious extortion group ShinyHunters claims responsibility for European Commission cloud breach, leaking 90GB of data including SSO directories and DKIM keys.

The notorious extortion group ShinyHunters has claimed responsibility for the European Commission's cloud breach, detected on March 24. As proof, the group leaked a 90GB archive of data, purportedly from AWS and NextCloud environments. This leaked data includes critical items such as full Single Sign-On (SSO) user directories and DKIM signing keys, significantly increasing the potential for targeted phishing, email spoofing, and further attacks. While the Commission maintains the incident was contained to public-facing systems, the specific nature of the leaked credentials raises serious security concerns and suggests a higher impact than initially reported.

Sources & References(when first published)

Article Author

Jason Gomes

Jason Gomes

• Cybersecurity Practitioner

Cybersecurity professional with over 10 years of specialized experience in security operations, threat intelligence, incident response, and security automation. Expertise spans SOAR/XSOAR orchestration, threat intelligence platforms, SIEM/UEBA analytics, and building cyber fusion centers. Background includes technical enablement, solution architecture for enterprise and government clients, and implementing security automation workflows across IR, TIP, and SOC use cases.

Threat Intelligence & AnalysisSecurity Orchestration (SOAR/XSOAR)Incident Response & Digital ForensicsSecurity Operations Center (SOC)SIEM & Security AnalyticsCyber Fusion & Threat SharingSecurity Automation & IntegrationManaged Detection & Response (MDR)

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AWSEuropean Unioncloud breachdata exfiltrationgovernment

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