The menace actor referred to as Paper Werewolf has been noticed solely concentrating on Russian entities with a brand new implant known as PowerModul.
The exercise, which occurred between July and December 2024, singled out organizations within the mass media, telecommunications, building, authorities entities, and vitality sectors, Kaspersky stated in a brand new report printed Thursday.
Paper Werewolf, also called GOFFEE, is assessed to have performed at the very least seven campaigns since 2022, based on BI.ZONE, with the assaults primarily geared toward authorities, vitality, monetary, media, and different organizations.
Attack chains mounted by the menace actor have additionally been noticed incorporating a disruptive element, whereby the intrusions transcend distributing malware for espionage functions to additionally change passwords belonging to worker accounts.
The assaults themselves are initiated through phishing emails that include a macro-laced lure doc, which, upon opening and enabling macros, paves the way in which for the deployment of a PowerShell-based distant entry trojan referred to as PowerRAT.
The malware is designed to ship a next-stage payload, usually a customized model of the Mythic framework agent referred to as PowerTaskel and QwakMyAgent. One other instrument within the menace actor’s arsenal is a malicious IIS module known as Owowa, which is used for retrieving Microsoft Outlook credentials entered by customers on the net shopper.
The newest set of assaults documented by Kaspersky begins with a malicious RAR archive attachment containing an executable that masquerades as a PDF or a Phrase doc utilizing a double extension (i.e., *.pdf.exe or *.doc.exe). When the executable is launched, the decoy file is downloaded from a distant server and proven to the consumer, whereas the an infection proceeds to the subsequent stage within the background.
“The file itself is a Home windows system file (explorer.exe or xpsrchvw.exe), with a part of its code patched with a malicious shellcode,” it stated. “The shellcode is much like what we noticed in earlier assaults, however as well as incorporates an obfuscated Mythic agent, which instantly begins speaking with the command-and-control (C2) server.”
The alternate assault sequence is much more elaborate, utilizing a RAR archive embedding a Microsoft Workplace doc with a macro that acts as a dropper to deploy and launch PowerModul, a PowerShell script able to receiving and executing extra PowerShell scripts from the C2 server.
The backdoor is claimed to have been used for the reason that begin of 2024, with the menace actors initially utilizing it to obtain and execute PowerTaskel on compromised hosts. A few of the different payloads dropped by PowerModul are listed beneath –
- FlashFileGrabber, which is used to steal information from detachable media, equivalent to flash drives, and exfiltrate them to the C2 server
- FlashFileGrabberOffline, a variant of FlashFileGrabber that searches detachable media for information with particular extensions, and when discovered, copies them to the native disk throughout the “%TEMPpercentCacheStoreconnect” folder
- USB Worm, which is able to infecting detachable media with a duplicate of PowerModul
PowerTaskel is functionally much like PowerModul in that it is also designed to run PowerShell scripts despatched by the C2 server. However as well as, it will possibly ship details about the focused atmosphere within the type of a “checkin” message, in addition to execute different instructions obtained from the C2 server as duties. It is also outfitted to escalate privileges utilizing the PsExec utility.
In at the very least one occasion, PowerTaskel has been discovered to obtain a script with a FolderFileGrabber element that, in addition to replicating the options of FlashFileGrabber, contains the power to collect information from distant programs through a hardcoded community path utilizing the SMB protocol.
“For the primary time, they employed Phrase paperwork with malicious VBA scripts for preliminary an infection,” Kaspersky stated. “Lately, we’ve noticed that GOFFEE is more and more abandoning using PowerTaskel in favor of the binary Mythic agent throughout lateral motion.”
The event comes as BI.ZONE attributed one other menace group known as Sapphire Werewolf to a phishing marketing campaign that distributes an up to date model of the open-source Amethyst Stealer.
The stealer retrieves “credentials from Telegram and numerous browsers, together with Chrome, Opera, Yandex, Courageous, Orbitum, Atom, Kometa, and Edge Chromium, in addition to FileZilla and SSH configuration information,” the Russian firm stated, including it will possibly additionally seize paperwork, together with these saved on detachable media.
