A recent phishing campaign has been identified targeting Pakistan, employing tax-themed lures and malicious Microsoft Common Console Document (MSC) files to deliver a stealthy backdoor payload. The campaign, tracked by cybersecurity firm Securonix as FLUX#CONSOLE, highlights the evolving sophistication of phishing techniques. The attack begins with a double-extension file, such as .pdf.msc, which masquerades as a legitimate PDF. When opened, it executes embedded JavaScript through the Microsoft Management Console (MMC), bypassing standard detection mechanisms.
One of the notable decoy documents used is titled “Tax Reductions, Rebates and Credits 2024,” mimicking an official file from Pakistan’s Federal Board of Revenue (FBR). The malicious code retrieves and displays this decoy while covertly loading a DLL file named DismCore.dll. This file establishes persistence using scheduled tasks and sets up communication with a remote server, enabling attackers to execute commands and exfiltrate sensitive data from compromised systems.
The attack demonstrates advanced obfuscation techniques, including deeply concealed malware within DLL files and highly encoded JavaScript in its initial stages. Researchers noted that MSC files, often used in legitimate Windows administrative workflows, represent an evolution of the widely abused LNK file. This tactic allows threat actors to deliver malicious payloads while blending into normal operations, making detection and analysis challenging for security teams.
While attribution remains uncertain, the Patchwork threat group is suspected due to their history of using similar tax-related documents in past campaigns. However, Securonix researchers caution that threat actors often reuse phishing lures, making definitive attribution difficult. This campaign underscores the increasing complexity of phishing attacks and the need for heightened vigilance against evolving file-based exploits targeting critical regions.
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