Hackers Exploiting Follina Bug to Deploy Rozena Backdoor

A newly noticed phishing campaign is leveraging the not too long ago disclosed Follina security vulnerability to distribute a beforehand undocumented backdoor on Windows programs.

“Rozena is a backdoor malware that is capable of injecting a distant shell relationship again to the attacker’s device,” Fortinet FortiGuard Labs researcher Cara Lin mentioned in a report this 7 days.

Tracked as CVE-2022-30190, the now-patched Microsoft Windows Aid Diagnostic Software (MSDT) distant code execution vulnerability has occur underneath large exploitation in the latest weeks ever because it came to light-weight in late Might 2022.

The starting off point for the newest attack chain observed by Fortinet is a weaponized Business document that, when opened, connects to a Discord CDN URL to retrieve an HTML file (“index.htm”) that, in convert, invokes the diagnostic utility utilizing a PowerShell command to down load subsequent-phase payloads from the exact CDN attachment area.

This involves the Rozena implant (“Word.exe”) and a batch file (“cd.bat”) that is made to terminate MSDT processes, set up the backdoor’s persistence by usually means of Windows Registry modification, and obtain a harmless Phrase doc as a decoy.

The malware’s core function is to inject shellcode that launches a reverse shell to the attacker’s host (“microsofto.duckdns[.]org”), in the end permitting the attacker to just take command of the procedure expected to monitor and seize facts, although also preserving a backdoor to the compromised process.

The exploitation of the Follina flaw to distribute malware by way of destructive Phrase paperwork comes as social engineering attacks relying on Microsoft Excel, Windows shortcut (LNK), and ISO impression documents as droppers to deploy malware this sort of as Emotet, QBot, IcedID, and Bumblebee to a victim’s device.

The droppers are reported to be dispersed through email messages that include straight the dropper or a password-shielded ZIP as an attachment, an HTML file that extracts the dropper when opened, or a connection to download the dropper in the entire body of the email.

Even though attacks spotted in early April prominently highlighted Excel information with XLM macros, Microsoft’s final decision to block macros by default around the very same time is said to have forced the threat actors to pivot to option methods like HTML smuggling as well as .LNK and .ISO documents.

Past thirty day period, Cyble disclosed information of a malware resource termed Quantum that’s currently being sold on underground community forums so as to equip cybercriminal actors with capabilities to create malicious .LNK and .ISO documents.

It is worthy of noting that macros have been a tried using-and-tested attack vector for adversaries on the lookout to fall ransomware and other malware on Windows methods, regardless of whether it be as a result of phishing e-mail or other usually means.

Microsoft has due to the fact quickly paused its plans to disable Workplace macros in data files downloaded from the internet, with the corporation telling The Hacker News that it is really taking the time to make “extra changes to enrich usability.”

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Some areas of this write-up are sourced from:
thehackernews.com