MuddyWater’s UDPGangster Backdoor: A New Threat Targeting Turkey, Israel, and Azerbaijan
The Iranian state-sponsored hacking group known as MuddyWater has recently been identified deploying a sophisticated backdoor named UDPGangster, which utilizes the User Datagram Protocol (UDP) for command-and-control (C2) communications. This development marks a significant evolution in MuddyWater’s cyber espionage tactics, particularly targeting entities in Turkey, Israel, and Azerbaijan.
Spear-Phishing Tactics and Initial Compromise
The attack campaign begins with meticulously crafted spear-phishing emails designed to deceive recipients into opening malicious attachments. These emails often impersonate legitimate organizations to enhance their credibility. For instance, some messages have been observed masquerading as communications from the Turkish Republic of Northern Cyprus Ministry of Foreign Affairs, inviting recipients to an online seminar titled Presidential Elections and Results.
Attached to these emails are files such as seminer.zip or seminer.doc. When opened, these documents prompt users to enable macros, a common feature in Microsoft Word that, when activated, executes embedded Visual Basic for Applications (VBA) code. This VBA code serves as the initial stage of the malware deployment.
Execution and Deployment of UDPGangster
Once macros are enabled, the malicious VBA script decodes Base64-encoded data hidden within the document and writes the decoded content to a file named ui.txt located in the C:\Users\Public\ directory. Subsequently, the script utilizes the Windows API function CreateProcessA to execute this file, thereby launching the UDPGangster payload.
To divert the user’s attention and mask the malicious activity, the VBA script displays a decoy image. Notably, in some instances, this image has been a Hebrew-language notice from Israeli telecommunications provider Bezeq, detailing supposed service disconnections in various cities during early November 2025. This tactic suggests a deliberate attempt to target Israeli users and adds a layer of social engineering to the attack.
Persistence Mechanisms and Anti-Analysis Techniques
UDPGangster is engineered with robust mechanisms to maintain persistence on compromised systems and evade detection. Upon execution, it copies itself to the %AppData%\RoamingLow directory under the name SystemProc.exe and modifies the Windows Registry to ensure it runs at startup.
To resist analysis and thwart security researchers, UDPGangster performs a series of checks, including:
– Debugger Detection: Utilizes Windows APIs to determine if the process is being debugged.
– System Configuration Analysis: Checks CPU core count and RAM size, terminating if the system has less than 2048 MB of RAM or a single-core CPU.
– Virtualization Detection: Retrieves network adapter information to identify MAC addresses associated with virtual machine vendors and scans for processes related to virtualization tools like VBoxService.exe, VBoxTray.exe, vmware.exe, and vmtoolsd.exe.
– Registry Scans: Searches for registry keys linked to known virtualization vendors, such as VBox, VMBox, QEMU, VIRTUAL, VIRTUALBOX, VMWARE, and Xen.
– Sandbox Evasion: Looks for indicators of sandbox environments and debugging tools to avoid execution in controlled settings.
Only after these checks confirm a non-analysis environment does UDPGangster proceed with its operations.
Command-and-Control Communication via UDP
A distinguishing feature of UDPGangster is its use of UDP for C2 communications, specifically over port 1269. This choice is strategic, as UDP traffic is less commonly monitored compared to TCP-based protocols like HTTP or HTTPS, allowing the malware to bypass traditional network defenses.
Once active, UDPGangster connects to an external server at 157.20.182[.]75 and performs the following actions:
– System Information Gathering: Collects data about the compromised system.
– Command Execution: Runs commands using cmd.exe.
– File Transmission: Exfiltrates files from the infected system.
– Payload Deployment: Downloads and executes additional malicious payloads as instructed by the C2 server.
Implications and Recommendations
The deployment of UDPGangster underscores MuddyWater’s continuous evolution and sophistication in cyber espionage activities. By leveraging UDP for C2 communications and implementing extensive anti-analysis techniques, the group enhances its ability to evade detection and maintain prolonged access to targeted systems.
Organizations, particularly those in Turkey, Israel, and Azerbaijan, should exercise heightened vigilance. It is crucial to be cautious of unsolicited emails, especially those prompting the activation of macros in attached documents. Implementing robust email filtering, educating users about the risks of enabling macros, and deploying advanced endpoint detection and response (EDR) solutions can significantly mitigate the risk of such sophisticated attacks.
