Cybercriminals Use Fake Software to Spread Dangerous FakeBat Malware

The surge in malware infections worldwide has unveiled a new player in the cybercrime arena: FakeBat malware. FakeBat, also known by aliases such as EugenLoader and PaykLoader, has caused unprecedented disruptions, targeting individuals and companies searching for widely-used business software. This malicious software, whose origins trace back to the nefarious actor Eugenfest, is part of a sophisticated Malware-as-a-Service (MaaS) operation managed by the group UNC4536, with monitoring and naming handled by Google’s threat intelligence team under the moniker NUMOZYLOD. This insidious malware has been ruthlessly efficient in leveraging fake software searches to propagate its payloads.

Central to these attacks is a trojanized MSIX installer. This installer, far from being just a benign file, conceals within it a PowerShell script that functions as the harbinger of further chaos by downloading additional malware onto the victim’s system. Drive-by downloads play a crucial role in these cyberattacks, redirecting users searching for popular software to counterfeit sites hosting corrupted MSIX installers. Such tactics have led to the proliferation of numerous notorious malware families, including but not limited to IcedID, RedLine Stealer, Lumma Stealer, SectopRAT (ArechClient2), and Carbanak. The latter is known for its association with the FIN7 cybercrime group, making this campaign particularly alarming.

The Strategy Behind the Cyberattacks

One of the most disturbing aspects of the UNC4536 group’s tactics is their use of malvertising. They cunningly disguise their MSIX installers as legitimate applications that everyday users might search for online. Applications like Brave, KeePass, Notion, Steam, and Zoom are prime targets for these fake installers. These deceptive installers are hosted on websites meticulously crafted to appear legitimate, thus luring unsuspecting users into a trap. Once these installers are downloaded, they utilize a configuration setup called "startScript," which allows the execution of scripts before the main application even starts. This tactic provides an open gateway for the malware to install itself surreptitiously.

UNC4536 operates primarily as a malware distributor, and FakeBat serves as their primary tool in this illicit trade. By distributing FakeBat, the group ensures that subsequent payloads reach their intended targets, including business partners such as the infamous FIN7. Upon installation, the malware collects sensitive system information, such as operating system details, domain affiliation, and installed antivirus products. Certain variants of this malware also gather the public IPv4 and IPv6 addresses of the host, sending this crucial information to their command-and-control servers. To ensure its persistent presence on the affected system, FakeBat often creates shortcuts in the StartUp folder, thus maintaining its malign influence even after reboots.

Broader Implications and Similar Threats

The emergence of FakeBat as a significant threat coincides with revelations from Mandiant regarding another nefarious downloader called EMPTYSPACE. EMPTYSPACE, which shares characteristics with FakeBat, has been used by a financially motivated threat cluster identified as UNC4990. This group has been notably active in targeting entities within Italy, focusing on data exfiltration and cryptojacking. The similarity between these two campaign tactics highlights a troubling trend in the cyber threat landscape, where cybercriminals continually refine and perfect their techniques to maximize impact and evade detection.

The methods used by these threat actors underscore a growing sophistication in cyberattacks. Both FakeBat and EMPTYSPACE illustrate the lengths to which cybercriminals will go to compromise systems, steal data, and create systemic disruptions. The fact that these operations often involve trojanized installers masquerading as trusted software emphasizes the critical need for vigilance. Cybersecurity professionals must continually adapt and evolve their defenses, employing advanced threat detection measures to counteract these evolving threats.

The Importance of Vigilance and Advanced Threat Detection

The global surge in malware infections has introduced a new threat: FakeBat malware. Also known as EugenLoader and PaykLoader, FakeBat has caused significant disruptions, targeting both individuals and businesses looking for popular business software. This malicious software originates from the group UNC4536, tied to the cybercriminal Eugenfest, and is part of an advanced Malware-as-a-Service (MaaS) scheme. Google’s threat intelligence team, NUMOZYLOD, monitors and names this threat. FakeBat has efficiently exploited fake software searches to distribute its payloads.

At the core of these attacks is a trojanized MSIX installer. Disguised as a legitimate file, it hides a PowerShell script that downloads additional malware onto the victim’s system. Drive-by downloads are pivotal to these cyberattacks, redirecting unsuspecting users to fake sites with corrupted MSIX installers. This strategy has led to the spread of numerous notorious malware families, including IcedID, RedLine Stealer, Lumma Stealer, SectopRAT (ArechClient2), and Carbanak. Carbanak is particularly concerning due to its ties with the infamous FIN7 cybercrime group.

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