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Void Banshee exploits CVE-2024-38112 zero

criticalVulnerability exploited in the wildimportance 60CVE-2024-38112CVE-2021-40444

Vulnerabilities mentionedAll →

CVEVulnerabilityCVSSEPSSFlagsAffectedExposurePublished
CVE-2021-40444
Remote Code Execution via MSHTML Rendering Engine in Microsoft Windows/Office (CVE-2021-40444)

CVE-2021-40444 is a remote code execution vulnerability in the Microsoft MSHTML browser rendering engine, which Microsoft Office documents can load on Windows systems. It is triggered when a user is convinced to open a specially crafted Office document containing a malicious ActiveX control hosted by the MSHTML engine (tracked as a path-traversal-class issue, CWE-22). A successful attacker gains the ability to run arbitrary code in the context of the logged-on user, with greater impact when that user has administrative rights. Any Windows system that can open Office documents is exposed, spanning Windows 7, 8.1, RT 8.1, Windows 10 (1507 through 21H1) and Windows Server 2004/2008. Exploitation is confirmed in the wild: Microsoft observed targeted attacks at disclosure, the flaw is in CISA's KEV with known ransomware use, and Microsoft released security updates on September 14, 2021.

Do: Apply Microsoft's security updates released September 14, 2021 for your Windows version immediately; this is a CISA KEV item with known ransomware use, so patching is treated as mandatory. As interim protection, keep Microsoft Defender Antivirus/Defender for Endpoint signatures current (enterprise detection build 1.349.22.0 or newer, with alerts appearing as 'Suspicious Cpl File Execution') and avoid opening untrusted Office documents, since exploitation requires user interaction with a crafted file.

8.897% KEV ransomware PoC ×2
  • microsoft MSHTML as shipped in the affected Windows releases
  • microsoft Windows 10 1507, 1607, 1809, 1909, 2004, 20H2, 21H1
  • microsoft Windows 7 all versions covered by Microsoft's September 2021 security updates
  • +4 more
masshundreds of millions of Windows PCs and servers (nearly all Windows desktop/laptop installs on affected versions at disclosure)
CVE-2024-38112
Windows MSHTML Platform Spoofing Vulnerability Exploited in the Wild (CVE-2024-38112)

CVE-2024-38112 is a spoofing flaw (CWE-451) in the Microsoft Windows MSHTML platform, the Windows component used to render web content, including by applications that embed the legacy Internet Explorer engine. It is triggered when a user interacts with attacker-controlled content rendered through MSHTML: the attack requires no privileges, travels over the network, and needs user interaction (UI:R per its CVSS vector), letting an attacker misrepresent critical UI information to the victim. Despite being classified as spoofing, the CVSS impact scores are high across confidentiality, integrity, and availability, and the CVSS base score is 7.5 (High). Any system running the affected Windows 10 (1507, 1607, 1809, 21H2, 22H2), Windows 11 (21H2, 22H2, 23H2), or Windows Server (2008, 2012, 2016, 2019) releases is affected. Exploitation is confirmed in the wild: Microsoft patched it as an actively exploited zero-day in July 2024, CISA added it to the Known Exploited Vulnerabilities catalog on 2024-07-09, and reporting indicates it had been exploited for over a year before the fix.

Do: Apply Microsoft's July 2024 security updates (Patch Tuesday) across all affected Windows 10, Windows 11, and Windows Server versions, prioritizing internet-facing and user workstations given confirmed in-the-wild exploitation and the 84.2% EPSS score. Until patched, remind users to avoid interacting with untrusted web or document content, since exploitation requires user interaction. Track the fix against CISA's KEV catalog deadlines and verify patch status on all endpoints.

7.584% KEV
  • Microsoft Windows 10 1507
  • Microsoft Windows 10 1607
  • Microsoft Windows 10 1809
  • +9 more
masshundreds of millions of Windows devices (essentially all desktops and servers on the listed Windows 10/11 and Windows Server releases)
Full article626 words · extracted from securityaffairs.com · click to collapse

Void Banshee APT group exploited the Windows zero-day CVE-2024-38112 to execute code via the disabled Internet Explorer.

An APT group tracked as Void Banshee was spotted exploiting the Windows zero-day CVE-2024-38112 (CVSS score of 7.5) to execute code through the disabled Internet Explorer.

The vulnerability is a Windows MSHTML Platform Spoofing Vulnerability. Successful exploitation of this vulnerability requires an attacker to take additional actions before exploitation to prepare the target environment. An attacker can trigger the issue by sending the victim a malicious file that the victim would have to execute.

Trend Micro researchers discovered that the flaw was actively exploited in the wild in May and reported it to Microsoft which addressed the zero-day with the July 2024 Patch Tuesday security updates.

Void Banshee was observed exploiting the CVE-2024-38112 flaw to drop the Atlantida info-stealer on the victims’ machines. The malware allows operators to gather system information and steal sensitive data, such as passwords and cookies, from multiple applications.

In the group’s attack chain, Void Banshee attempts to trick victims into opening zip archives containing malicious files disguised as book PDFs. The archives are disseminated in cloud-sharing websites, Discord servers, and online libraries, and other means. The APT group focuses on North America, Europe, and Southeast Asia.

“This zero-day attack is a prime example of how unsupported Windows relics are an overlooked attack surface that can still be exploited by threat actors to infect unsuspecting users with ransomware, backdoors, or as a conduit for other kinds of malware.” states Trend Micro.

Void Banshee exploited the disabled Internet Explorer process to run HTML Application (HTA) files using specially crafted .URL files with the MHTML protocol handler and the x-usc! directive. This technique resembles the exploitation of CVE-2021-40444, another MSHTML flaw that was exploited in zero-day attacks. The experts warn that this attack method is very concerning because Internet Explorer no longer receives updates or security fixes.

“In this attack, CVE-2024-38112 was used as a zero-day to redirect a victim by opening and using the system-disabled IE to a compromised website which hosted a malicious HTML Application (HTA)” states the report. “In the URL parameter of the internet shortcut file, we can see that Void Banshee specifically crafted this URL string using the MHTML protocol handler along with the x-usc! directive. This logic string opens the URL target in the native Internet Explorer through the iexplore.exe process.”

Void Banshee APT CVE-2024-38112

Attackers used the internet shortcut file to direct the victims to an attacker-controlled domain where an HTML file downloads the HTA stage of the infection chain. The researchers noticed that Void Banshee uses this HTML file to control the window view size of Internet Explorer, hiding browser information and hiding the download of the next infection stage from the victim.

By default, IE prompts users to open or save the HTML application, but the APT group disguised the HTA file as a PDF by adding spaces to the file extension. Upon running the HTA file, a series of scripts is executed, along with the LoadToBadXml .NET trojan loader, the Donut shellcode, and the Atlantida stealer.

“In this campaign, we have observed that even though users may no longer be able to access IE, threat actors can still exploit lingering Windows relics like IE on their machine to infect users and organizations with ransomware, backdoors, or as a proxy to execute other strains of malware.” Trend Micro concludes. “The ability of APT groups like Void Banshee to exploit disabled services such as IE poses a significant threat to organizations worldwide. Since services such as IE have a large attack surface and no longer receive patches, it represents a serious security concern to Windows users.”

Pierluigi Paganini

Follow me on Twitter: @securityaffairs and Facebook and Mastodon

(SecurityAffairs – hacking, CVE-2024-38112)



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