Full Report
The "EC2 Grouper" threat actor is a prolific group frequently detected in cloud environments. They are known for using consistent user agents and a specific security group naming convention (e.g., ec2group, ec2group12345) during attacks, making them easier to identify. However...
Analysis Summary
# Threat Actor: EC2 Grouper
## Attribution & Identity
**Identification:** EC2 Grouper, a prolific threat actor frequently detected in cloud environments (specifically AWS).
**Aliases/Associations:** None explicitly mentioned in the context, beyond the actor name itself.
## Activity Summary
The primary known activity involves operations within cloud environments, characterized by consistent and automated API calls suggesting resource hijacking is the primary objective, though this remains unconfirmed. Recent activity shows an attempt to evade detection by updating user agents to include unusual characters.
## Tactics, Techniques & Procedures
- **Initial Access:** Not explicitly detailed, but activity centers post-access within the cloud environment.
- **Reconnaissance:**
- `DescribeInstanceTypes`
- `DescribeRegions`
- `DescribeVpcs`
- **Resource Modification/Execution:**
- `CreateSecurityGroup` (used for establishing predictable security group naming conventions)
- `RunInstances`
- **Infrastructure Modification:**
- `CreateInternetGateway`
- `CreateVpc`
- **TTP Identifiers:** Use of consistent user agents (recently modified for evasion) and a specific security group naming convention (e.g., `ec2group`, `ec2group12345`).
- **MITRE ATT&CK IDs:** Not provided in the context.
## Targeting
- **Sectors:** Cloud Environments (specifically AWS).
- **Geography:** Not specified.
- **Victims:** Not specified.
## Tools & Infrastructure
- **Malware Families Used:** None explicitly named.
- **Infrastructure:** Utilizes legitimate **AWS tools for PowerShell**. No specific C2 infrastructure (URLs/IPs) mentioned.
## Implications
EC2 Grouper is a highly automated threat actor focused on cloud resource manipulation and potential hijacking within AWS. While their naming conventions offer initial detection signatures, these indicators are transient, and the actor is actively attempting evasion (via user agent modification), suggesting an evolving and persistent threat posture in the cloud landscape.
## Mitigations
- **Monitor Security Group Naming:** Implement strict policies against creating security groups matching known predictable patterns (`ec2group`, `ec2group12345`).
- **Analyze API Call Patterns:** Establish detection/alerting for automated sequences involving reconnaissance calls (`Describe*`) followed immediately by resource creation or modification (`CreateSecurityGroup`, `RunInstances`).
- **User Agent Monitoring:** Monitor for unusual or mutated characters within the user agents associated with AWS PowerShell tool usage.