Listen to this Post
Inside the Cyber Deception: A New Twist on Classic Threats
A recent phishing campaign has surfaced, utilizing a blend of outdated file formats, deceptive user account control (UAC) bypass techniques, and powerful obfuscation tactics to deploy the Remcos Remote Access Trojan (RAT) across Windows systems. This modern threat is a chilling example of how old vulnerabilities are being reimagined for contemporary cyberattacks. Analysts at ANY.RUN dissected this campaign using real-time sandbox technology, uncovering a layered infection chain that carefully avoids detection while embedding itself deep within the system. From the strategic use of .pif files to hijacking trusted system utilities, this operation is a masterclass in stealth, persistence, and exploitation.
How the Attack Unfolds
The campaign kicks off with a carefully crafted phishing email, often containing a compressed archive. Inside this archive lies an executable disguised with names like “FAKTURA,” designed to appeal to business users. When executed, this file activates the DBatLoader dropper, which interestingly uses .pif files — a legacy format from the DOS era. Though largely considered obsolete, .pif files remain executable on Windows, making them a subtle but potent delivery method.
Once activated, the loader sets off a complex chain of commands. One standout tactic involves using directories with misleading names like “C:\Windows ” (note the trailing space) to confuse the Windows file system and bypass UAC. The malware then initiates time-delay techniques by exploiting the built-in PING.EXE utility, sending echo requests to localhost. These delays hinder automated analysis tools and sandbox environments from properly tracking the malware’s real behavior.
Persistence is ensured via Windows’ scheduled tasks. A cleverly disguised task launches the malicious .pif file at every reboot, making the infection highly resilient. In the next stage, obfuscated scripts wrapped in BatCloak are used to stealthily download and run the final payload: Remcos RAT. To disable protection mechanisms, the malware employs extrac32.exe — a legitimate Windows utility — to exclude its directories from Windows Defender.
Once in the system, Remcos RAT injects itself into trusted processes such as SndVol.exe and colorcpl.exe. These are not just decoys — they are carefully selected targets that help the RAT operate under the radar. The injection points change with each infection, making traditional signature-based detection tools practically useless.
ANY.RUN’s sandbox logs every malicious behavior and maps it to the MITRE ATT\&CK framework. The findings reveal a campaign that thrives on Living Off the Land Binaries and Scripts (LOLBAS), further complicating defense efforts. Analysts stress the critical importance of dynamic sandbox analysis for timely and accurate detection. Monitoring unusual process behaviors, abnormal file paths, and suspicious network activities are all essential for identifying this type of threat early.
Security professionals are being urged to step up user training and adopt proactive defense tools that go beyond signature-based detection. As cybercriminals continue to breathe new life into outdated file types and hijack legitimate system utilities, it’s clear that the battle for endpoint security is far from over.
What Undercode Say:
The Evolution of Obsolete Formats into Cyber Weapons
Cybercriminals have long shown a knack for repurposing outdated technology, and this campaign is a prime example. The use of .pif files — long thought irrelevant — is a cunning move. By exploiting their backward compatibility, attackers sidestep security mechanisms that no longer prioritize these formats. The fact that .pif files are still executed by modern Windows versions is an oversight that’s now proving costly.
UAC Bypass Through Folder Name Manipulation
Manipulating folder names with trailing spaces is a low-tech trick with high-impact results. It exploits inconsistencies in how Windows interprets file paths, effectively fooling the system’s privilege escalation checks. This type of subversion indicates the attackers have deep knowledge of the operating system’s quirks.
Living Off the Land: Blurring the Line Between Malicious and Legitimate
The heavy use of LOLBAS tools like extrac32.exe and ping.exe shows how attackers increasingly rely on what’s already available in the system. These binaries are signed, trusted, and widely used — making them excellent tools for malware authors. It complicates detection because behavior that looks normal on the surface may mask dangerous operations underneath.
Remcos RAT: An Infostealer Disguised as a System Utility
Remcos isn’t new, but its deployment tactics are evolving. Its ability to inject into benign processes makes it stealthy, and the modular nature of its loader means that each infection can be uniquely tailored. This is what makes detection and remediation so difficult. By hiding inside colorcpl.exe or SndVol.exe, Remcos gains legitimacy in the eyes of the system and many antivirus tools.
Sandboxing as the First Line of Defense
ANY.RUN’s sandbox analysis proves that real-time behavioral analysis is indispensable. It captures evasive tactics that static detection cannot see. For organizations, sandboxing suspicious files before they reach users should be standard procedure. These environments expose command executions, scheduled tasks, and network connections that might otherwise remain hidden.
Endpoint Protection Needs an Overhaul
Endpoint security solutions often rely on signature-based or heuristic detection, which this campaign completely bypasses. It highlights the need for behavior-based threat detection engines that analyze how applications behave rather than what they look like. Integrating AI into endpoint protection could be a game-changer in these scenarios.
User Education Still Matters
Despite the technical sophistication of the malware, it all starts with a phishing email. Organizations must continue to invest in user training to reduce the chance of employees opening suspicious attachments. A well-informed user is the first and best line of defense.
Why the Threat Persists
The combination of stealth, persistence, and the use of legitimate tools makes this campaign extremely durable. It’s not just about gaining access — it’s about staying hidden long enough to do real damage. That’s what makes the Remcos RAT campaign a particularly dangerous threat in the wild.
Strategic Implications for Enterprises
For businesses, this type of threat is not just a cybersecurity issue — it’s a business continuity risk. A successful infection could lead to data breaches, reputational damage, or even financial losses through espionage or ransomware. Enterprises need to treat these campaigns as high-priority threats and align their cybersecurity strategies accordingly.
Detection vs. Prevention
Finally, this campaign shows that detection is no longer enough. Prevention, real-time analysis, and incident response need to be part of a comprehensive approach. Waiting to react after compromise is no longer a viable option in a landscape filled with increasingly advanced threats.
🔍 Fact Checker Results:
✅ Remcos RAT is a real, active malware used in modern attacks
✅ .pif files, though obsolete, are still executable in Windows systems
✅ UAC bypass via folder name manipulation has been documented and verified
📊 Prediction:
Cybercriminals will continue to revive old file types like .pif, .scr, or even .hlp, exploiting backward compatibility for stealth. We anticipate an increase in malware campaigns leveraging legitimate system binaries for injection and persistence. The use of sandbox-evading techniques will rise, forcing cybersecurity vendors to double down on behavior-based detection strategies and real-time threat intelligence solutions. 🛡️📈
References:
Reported By: cyberpress.org
Extra Source Hub:
https://www.facebook.com
Wikipedia
OpenAi & Undercode AI
Image Source:
Unsplash
Undercode AI DI v2
