Output Messenger Breach Incident Score: Analysis & Impact (SRISRI1767087399)

In this Rankiteo incident briefing, we review the Output Messenger breach identified under incident ID SRISRI1767087399.

The analysis begins with a detailed overview of Output Messenger's information like the linkedin page: https://www.linkedin.com/company/srimax, the number of followers: 51, the industry type: IT Services and IT Consulting and the number of employees: None employees

After the initial compromise, the video explains how Rankiteo's incident engine converts technical details into a normalized incident score. The incident score before the incident was 752 and after the incident was 751 with a difference of -1 which is could be a good indicator of the severity and impact of the incident.

In the next step of the video, we will analyze in more details the incident and the impact it had on Output Messenger and their customers.

On 01 April 2024, Output Messenger (Srimax) disclosed Cyber Espionage issues under the banner "Marbled Dust Exploits Zero-Day in Output Messenger for Cyber Espionage".

A Türkiye-affiliated threat actor exploited a zero-day security flaw in an Indian enterprise communication platform called Output Messenger as part of a cyber espionage attack campaign since April 2024.

The disruption is felt across the environment, affecting Output Messenger Server Manager, Output Messenger Client, and exposing User data, credentials, and sensitive information.

In response, moved swiftly to contain the threat with measures like Patch released (v2.0.63), removal of malicious payloads (OM.vbs, OMServerService.vbs, OMServerService.exe), and began remediation that includes Fix for CVE-2025-27920, enhanced authentication mechanisms.

The case underscores how Ongoing, teams are taking away lessons such as Zero-day exploits can be leveraged for targeted cyber espionage; reconnaissance plays a critical role in threat actor operations; timely patching is essential to mitigate risks, and recommending next steps like Apply the latest patch (v2.0.63) for Output Messenger, Monitor for connections to known malicious domains (e.g., api.wordinfos[.]com) and Implement multi-factor authentication (MFA) for sensitive systems.

Finally, we try to match the incident with the MITRE ATT&CK framework to see if there is any correlation between the incident and the MITRE ATT&CK framework.

The MITRE ATT&CK framework is a knowledge base of techniques and sub-techniques that are used to describe the tactics and procedures of cyber adversaries. It is a powerful tool for understanding the threat landscape and for developing effective defense strategies.

Rankiteo's analysis has identified several MITRE ATT&CK tactics and techniques associated with this incident, each with varying levels of confidence based on available evidence. Under the Initial Access tactic, the analysis identified Exploit Public-Facing Application (T1190) with high confidence (95%), supported by evidence indicating exploiting a zero-day vulnerability (CVE-2025-27920) in Output Messenger, Valid Accounts (T1078) with moderate to high confidence (80%), supported by evidence indicating authenticated access to the Output Messenger Server Manager, and Compromise Infrastructure: Domains (T1584.002) with moderate to high confidence (70%), supported by evidence indicating dNS hijacking or typosquatted domains to intercept credentials. Under the Execution tactic, the analysis identified Command and Scripting Interpreter: Windows Command Shell (T1059.003) with high confidence (90%), supported by evidence indicating responses executed via Windows command prompt (cmd /c) and User Execution: Malicious File (T1204.002) with moderate to high confidence (85%), supported by evidence indicating oM.vbs and OMServerService.vbs dropped in server startup folder. Under the Persistence tactic, the analysis identified Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder (T1547.001) with moderate to high confidence (85%), supported by evidence indicating oM.vbs and OMServerService.vbs dropped in server startup folder. Under the Defense Evasion tactic, the analysis identified Obfuscated Files or Information (T1027) with moderate to high confidence (70%), supported by evidence indicating golang backdoor (OMServerService.exe) placed in Users/public/videos directory and Exploitation for Defense Evasion (T1211) with moderate to high confidence (80%), supported by evidence indicating exploited CVE-2025-27920 to bypass security controls. Under the Credential Access tactic, the analysis identified Adversary-in-the-Middle (T1557) with moderate to high confidence (75%), supported by evidence indicating dNS hijacking or typosquatted domains to intercept credentials. Under the Discovery tactic, the analysis identified Account Discovery: Domain Account (T1087.002) with moderate to high confidence (70%), supported by evidence indicating reconnaissance to identify Output Messenger users. Under the Command and Control tactic, the analysis identified Application Layer Protocol: Web Protocols (T1071.001) with high confidence (90%), supported by evidence indicating backdoor communicated with hard-coded domain (api.wordinfos.com). Under the Exfiltration tactic, the analysis identified Exfiltration Over C2 Channel (T1041) with high confidence (95%), supported by evidence indicating data exfiltration to api.wordinfos.com, victim hostname data sent to C2. These correlations help security teams understand the attack chain and develop appropriate defensive measures based on the observed tactics and techniques.