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Memento Labs linked to Chrome zero-day exploitation in Operation ForumTroll

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Operation ForumTroll, discovered in March 2025, targeted Russian organizations and individuals using a zero-day vulnerability in Google Chrome (CVE-2025-2783). The campaign, also tracked as TaxOff/Team 46 by Positive Technologies and Prosperous Werewolf by BI.ZONE, delivered malware linked to the Italian spyware vendor Memento Labs. The attacks used phishing emails with malicious links to infect victims, targeting media outlets, universities, research centers, government organizations, financial institutions, and other organizations in Russia and Belarus. The malware, identified as LeetAgent and Dante, was used to steal data and maintain persistence on compromised systems. Memento Labs, formed after InTheCyber Group acquired Hacking Team, presented its Dante spyware at a conference in 2023. The malware was used in attacks dating back to at least 2022. The attacks involved sophisticated techniques to ensure only targeted victims were compromised. The zero-day vulnerability (CVE-2025-2783) was discovered and reported to Google by researchers at Kaspersky Lab earlier in 2025. The exploit bypassed Chrome's sandbox protections by exploiting a logic vulnerability in Chrome caused by an obscure quirk in the Windows OS. The exploit used pseudo handles to disable sandbox functionality, allowing unauthorized access to privileged processes. The exploit represents a new class of vulnerabilities that could affect other applications and Windows services. The group known as Mem3nt0 mori, also referred to as ForumTroll APT, is linked to Operation ForumTroll. The attacks began in March 2025 with highly personalized phishing emails inviting victims to the Primakov Readings forum. The flaw in Chrome stemmed from a logical oversight in Windows' handling of pseudo handles, allowing attackers to execute code in Chrome's browser process. Google patched the issue in version 134.0.6998.177/.178. Firefox developers found a related issue in their browser, addressed as CVE-2025-2857. Kaspersky's researchers concluded that Mem3nt0 mori leveraged Dante-based components in the ForumTroll campaign, marking the first observed use of this commercial spyware in the wild. The discovery underscores ongoing risks from state-aligned and commercial surveillance vendors. Kaspersky urged security researchers to examine other software and Windows services for similar pseudo-handle vulnerabilities. In a new wave of attacks detected in October 2025, the threat actor targeted individuals in Russia, specifically scholars in political science, international relations, and global economics, working at major Russian universities and research institutions. The latest attack wave used emails claiming to be from eLibrary, a Russian scientific electronic library, with messages sent from the address 'support@e-library[.]wiki'. The domain was registered in March 2025, six months before the start of the campaign, indicating preparations for the attack had been underway for some time. The emails contained links to a malicious site to download a plagiarism report, which, when clicked, downloaded a ZIP archive named with the victim's last name, first name, and patronymic. The links were designed for one-time use, displaying a Russian language message stating 'Download failed, please try again later' if accessed more than once. The archive contained a Windows shortcut (LNK) that, when executed, ran a PowerShell script to download and launch a PowerShell-based payload from a remote server. The payload contacted a URL to fetch a final-stage DLL and persist it using COM hijacking, also downloading and displaying a decoy PDF to the victim. The final payload was a command-and-control (C2) and red teaming framework known as Tuoni, enabling remote access to the victim's Windows device. ForumTroll has been targeting organizations and individuals in Russia and Belarus since at least 2022.

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  1. 27.10.2025 18:37 5 articles · 1mo ago

    Memento Labs linked to Chrome zero-day exploitation in Operation ForumTroll

    The group known as Mem3nt0 mori, also referred to as ForumTroll APT, is linked to Operation ForumTroll. The attacks began in March 2025 with highly personalized phishing emails inviting victims to the Primakov Readings forum. The flaw in Chrome stemmed from a logical oversight in Windows' handling of pseudo handles, allowing attackers to execute code in Chrome's browser process. Google patched the issue in version 134.0.6998.177/.178. Firefox developers found a related issue in their browser, addressed as CVE-2025-2857. Kaspersky's researchers concluded that Mem3nt0 mori leveraged Dante-based components in the ForumTroll campaign, marking the first observed use of this commercial spyware in the wild. The discovery underscores ongoing risks from state-aligned and commercial surveillance vendors. Kaspersky urged security researchers to examine other software and Windows services for similar pseudo-handle vulnerabilities. In a new wave of attacks detected in October 2025, the threat actor targeted individuals in Russia, specifically scholars in political science, international relations, and global economics, working at major Russian universities and research institutions. The latest attack wave used emails claiming to be from eLibrary, a Russian scientific electronic library, with messages sent from the address 'support@e-library[.]wiki'. The domain was registered in March 2025, six months before the start of the campaign, indicating preparations for the attack had been underway for some time. The emails contained links to a malicious site to download a plagiarism report, which, when clicked, downloaded a ZIP archive named with the victim's last name, first name, and patronymic. The links were designed for one-time use, displaying a Russian language message stating 'Download failed, please try again later' if accessed more than once. The archive contained a Windows shortcut (LNK) that, when executed, ran a PowerShell script to download and launch a PowerShell-based payload from a remote server. The payload contacted a URL to fetch a final-stage DLL and persist it using COM hijacking, also downloading and displaying a decoy PDF to the victim. The final payload was a command-and-control (C2) and red teaming framework known as Tuoni, enabling remote access to the victim's Windows device. ForumTroll has been targeting organizations and individuals in Russia and Belarus since at least 2022.

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