Threat Overview

The Security Operations Center (SOC) has received a critical threat report published by AlienVault on May 12, 2025. The report details the activities of Marbled Dust, a Türkiye-affiliated espionage threat actor, which has been exploiting a zero-day vulnerability in Output Messenger since April 2024. This campaign targets Kurdish military entities in Iraq, allowing the actor to deliver malicious files and exfiltrate sensitive data.

Marbled Dust’s operations represent a significant shift in their capabilities, indicating an increased level of technical sophistication. The zero-day vulnerability, identified as CVE-2025-27920, resides in the Output Messenger Server Manager application. This flaw enables authenticated users to upload malicious files to the server’s startup directory, facilitating further exploitation.

Attack Chain and Tactics

The attack chain employed by Marbled Dust involves several sophisticated steps:

1. Authenticated Access: The threat actor gains authenticated access to the target system, likely through compromised credentials or social engineering techniques.
2. Exploitation of Vulnerability: Once inside, Marbled Dust exploits the zero-day vulnerability (CVE-2025-27920) in Output Messenger Server Manager to upload malicious files to the server’s startup directory.
3. Deployment of Backdoors: The actor deploys GoLang backdoors designed for data exfiltration and command execution, allowing them to maintain persistent access and control over the compromised system.

In addition to these core tactics, Marbled Dust employs DNS hijacking and uses typo-squatted domains to intercept credentials. These methods enhance their ability to infiltrate and sustain operations within the target environment.

Impact and Implications

The exploitation of CVE-2025-27920 poses a significant risk to organizations using Output Messenger Server Manager. The vulnerability allows for unauthorized file uploads, which can lead to the deployment of malicious payloads and data exfiltration. This campaign underscores the importance of robust security measures and continuous monitoring to detect and mitigate such threats.

Recommendations

To protect against Marbled Dust’s activities and similar threats, organizations should consider the following recommendations:

1. Patch Management: Ensure that all software, including Output Messenger Server Manager, is kept up-to-date with the latest security patches. Regularly review and apply updates to mitigate known vulnerabilities.
2. Access Controls: Implement strict access controls and multi-factor authentication (MFA) to prevent unauthorized access to critical systems. Limit user permissions based on the principle of least privilege.
3. Network Monitoring: Deploy advanced network monitoring tools to detect suspicious activities, such as DNS hijacking and unusual file uploads. Regularly review logs for anomalies that may indicate a compromise.
4. User Education: Conduct regular training sessions to educate employees about phishing attacks, social engineering tactics, and the importance of strong password practices.
5. Incident Response Plan: Develop and maintain an incident response plan to quickly detect, respond to, and recover from security incidents. Regularly test the plan through tabletop exercises and simulations.

Conclusion

The Marbled Dust campaign highlights the evolving threat landscape and the need for organizations to remain vigilant against sophisticated cyber threats. By understanding the tactics employed by this threat actor and implementing robust security measures, organizations can better protect their assets and mitigate potential risks.

For more detailed information, please refer to the following external references:

1. Microsoft Security Blog: Marbled Dust leverages zero-day in Output Messenger for regional espionage
   URL: https://www.microsoft.com/en-us/security/blog/2025/05/12/marbled-dust-leverages-zero-day-in-output-messenger-for-regional-espionage

2. AlienVault OTX Pulse
   URL: https://otx.alienvault.com/pulse/68221f112932c07e56cb0096