infostealer Archives

Winsage

May 25, 2025

Windows Passwords Are Under Attack — Do These 7 Things Now

Microsoft Windows is a target for cybercriminals, particularly regarding password theft. Trend Micro has reported an increase in fraudulent Captcha attacks that trick users into executing malicious commands through the Windows Run dialog, leading to data theft and malware infections. These attacks utilize PowerShell and can deploy various malware types, including Lumma Stealer and AsyncRAT. Despite efforts to disrupt the Lumma Stealer network, threats persist, exploiting legitimate platforms. Microsoft recommends users adopt safer online practices and outlines seven mitigations for organizations: disable access to the Run dialog, apply least privilege, restrict access to unapproved tools, monitor unusual behavior, harden browser configurations, enable memory protection, and invest in user education.

Tech Optimizer

May 23, 2025

Cloudflare, Microsoft & police disrupt global malware service

Cloudflare, in collaboration with Microsoft and international law enforcement, has dismantled the infrastructure of LummaC2, an information-stealing malware service. This initiative led to the seizure and blocking of malicious domains and disrupted digital marketplaces used by criminals. Lumma Stealer operates as a subscription service providing threat actors access to a central panel for customized malware builds and stolen data retrieval. The stolen information includes credentials, cryptocurrency wallets, and sensitive data, posing risks of identity theft and financial fraud. Lumma Stealer was first identified on Russian-language crime forums in early 2023 and has since migrated to Telegram for distribution. Its proliferation is facilitated by social engineering campaigns, including deceptive pop-ups and bundled malware in cracked software. Cloudflare implemented measures to block access to Lumma's command and control servers and collaborated with various authorities to prevent the criminals from regaining control. Mitigation strategies for users include restricting unknown scripts, limiting password storage in browsers, and using reputable endpoint protection tools. The operation has significantly hindered Lumma's operations and aims to undermine the infostealer-as-a-service model contributing to cybercrime.

Tech Optimizer

May 21, 2025

Lumma Stealer: Breaking down the delivery techniques and capabilities of a prolific infostealer

Microsoft has monitored Lumma Stealer, an infostealer malware used by financially motivated threat actors. Lumma Stealer, also known as LummaC2, functions as a malware-as-a-service (MaaS) solution that extracts data from browsers and applications, including cryptocurrency wallets. The entity behind Lumma is identified as Storm-2477, which maintains the malware and its command-and-control (C2) infrastructure. Affiliates can create malware binaries and manage C2 communications through a panel provided by Storm-2477. Ransomware groups have integrated Lumma Stealer into their operations. Lumma Stealer employs various delivery techniques, including phishing emails, malvertising, drive-by downloads, Trojanized applications, and abuse of legitimate services. Specific campaigns have been identified, such as one in April 2025 that used EtherHiding and ClickFix techniques to deliver Lumma Stealer via compromised websites. Another campaign on April 7, 2025, targeted Canadian organizations with emails containing invoice lures that led to malicious downloads. The malware is developed using C++ and ASM, employing advanced obfuscation techniques to evade detection. It can extract a wide range of user data, including browser credentials, cryptocurrency wallet information, and user documents. Lumma Stealer maintains a robust C2 infrastructure with multiple hardcoded and fallback C2 servers, utilizing encryption methods to secure communications. Microsoft's Digital Crimes Unit has disrupted Lumma Stealer's infrastructure by blocking approximately 2,300 malicious domains. Recommendations to mitigate the impact of Lumma Stealer include strengthening Microsoft Defender configurations, implementing multifactor authentication, and utilizing phishing-resistant authentication methods. Microsoft Defender products can detect and block activities associated with Lumma Stealer, providing alerts and insights for incident response.

Winsage

May 8, 2025

Windows 0-Day Vulnerability Exploited in Wild to Deploy Play ransomware

Threat actors associated with the Play ransomware operation exploited a zero-day vulnerability in Microsoft Windows, identified as CVE-2025-29824, before a patch was released on April 8, 2025. This vulnerability affects the Windows Common Log File System (CLFS) driver, allowing attackers to elevate their privileges to full system access. The Play ransomware group targeted an unnamed organization in the United States, likely gaining initial access through a public-facing Cisco Adaptive Security Appliance (ASA). During this intrusion, no ransomware payload was deployed; instead, the attackers used a custom information-stealing tool named Grixba. Microsoft attributed this activity to the threat group Storm-2460, known for deploying PipeMagic malware. The exploitation affected various sectors, including IT, real estate in the U.S., finance in Venezuela, software in Spain, and retail in Saudi Arabia. The vulnerability received a CVSS score of 7.8 and was addressed in Microsoft's April 2025 Patch Tuesday updates. The attack involved creating files in the path C:ProgramDataSkyPDF, injecting a DLL into the winlogon.exe process, extracting credentials from LSASS memory, creating new administrator users, and establishing persistence. The Play ransomware group has been active since June 2022 and employs double-extortion tactics. Organizations are urged to apply the security updates released on April 8, 2025, especially for vulnerable Windows versions, while Windows 11 version 24H2 is not affected due to existing security mitigations.

Winsage

May 7, 2025

Play ransomware affiliate leveraged zero-day to deploy malware

The Play ransomware gang exploited a critical vulnerability in the Windows Common Log File System, identified as CVE-2025-29824, which has a CVSS score of 7.8 and is categorized as a "Use after free" vulnerability. This flaw allows an authorized attacker to elevate privileges locally and has been confirmed to be exploited in real-world attacks. The U.S. Cybersecurity and Infrastructure Security Agency (CISA) added it to its Known Exploited Vulnerabilities catalog in April. Microsoft addressed this vulnerability during its April Patch Tuesday security updates, acknowledging its exploitation in limited attacks targeting various sectors in the U.S. and Saudi Arabia. Researchers from Symantec reported that the Play ransomware gang used the CVE-2025-29824 exploit in an attack against a U.S. organization before the public disclosure and patching of the vulnerability. The attackers utilized the Grixba infostealer tool and initially exploited a public-facing Cisco ASA firewall to gain entry. They deployed tools to gather information, escalated privileges using the CVE-2025-29824 exploit, and executed malicious scripts to steal credentials. The exploit took advantage of race conditions in driver memory handling, allowing kernel access and manipulation of files. Before the patch was released, the exploit was reportedly used by multiple threat actors, and Microsoft linked it to other malware.

Winsage

May 7, 2025

Play ransomware exploited Windows logging flaw in zero-day attacks

The Play ransomware gang exploited a critical vulnerability in the Windows Common Log File System, identified as CVE-2025-29824, to execute zero-day attacks, gaining SYSTEM privileges and deploying malware. Microsoft recognized this flaw and issued a patch during last month's Patch Tuesday. The gang targeted sectors including IT and real estate in the U.S., the financial sector in Venezuela, a Spanish software company, and retail in Saudi Arabia. They used the PipeMagic backdoor malware to deploy the CVE-2025-29824 exploit and install ransomware payloads. Symantec's Threat Hunter Team linked these activities to the Play ransomware-as-a-service operation, noting the use of the Grixba infostealer tool. The Play ransomware group, active since at least June 2022, employs double-extortion tactics and has compromised approximately 300 organizations globally as of October 2023. Notable victims include Rackspace, Arnold Clark, the City of Oakland, Dallas County, Antwerp, and Microchip Technology.

Winsage

April 27, 2025

New Security Warning After 1 Billion Windows Users Told Do Not Delete

Microsoft's recent security update for Windows has raised concerns among users due to the introduction of a new vulnerability. The update, intended to address the CVE-2025-21204 vulnerability, inadvertently created a folder named inetpub, which Microsoft claims is essential for user protection. Security researcher Kevin Beaumont has warned that this update has introduced a denial of service vulnerability that allows non-admin users to halt future Windows security updates. Microsoft has classified the issue as moderate in severity and suggested that deleting the inetpub symlink and retrying the update may resolve the problem. The report has been forwarded to the Windows security team for potential further action.

Tech Optimizer

April 18, 2025

Breached Identities and Infostealers: One of the Largest Ongoing Data Leak in History

Breached identities due to infostealer malware are a significant threat to corporate information security in 2024. Infostealers are a type of remote access trojan that exfiltrate sensitive data, including saved credentials, session cookies, browser history, crypto wallet information, screen captures, and host data. Infections often stem from downloading cracked software, malicious advertising, fake Windows updates, and repackaged games. Infostealers do not require local administrative privileges, making them easy to execute. Threat actors primarily aim to profit from breached bank accounts and crypto wallets, often bypassing multi-factor authentication by targeting session cookies. They also seek credentials for subscription services and corporate access. Research shows that 90% of breached companies had leaked corporate credentials in a stealer log, with 78% experiencing leaks within six months of a breach. In comparison, 76% of similar companies without breaches had experienced a corporate stealer log compromise. The investigation identified high-criticality credentials from various corporate applications, indicating that a single user often has access to multiple credentials. The rise of infostealer malware represents a broad threat, encompassing a wide range of sensitive data. Organizations are advised to implement strategies such as restricting download privileges, avoiding illegal content, disabling macros, and regularly updating software to mitigate risks associated with infostealer malware.

Winsage

April 7, 2025

EncryptHub’s dual life: Cybercriminal vs Windows bug-bounty researcher

EncryptHub has been linked to breaches affecting 618 organizations and is associated with the disclosure of two Windows zero-day vulnerabilities, CVE-2025-24061 and CVE-2025-24071, to Microsoft. The vulnerabilities were addressed during the March 2025 Patch Tuesday updates, and the reporter was acknowledged as 'SkorikARI with SkorikARI.' Investigations revealed a connection between EncryptHub and SkorikARI, following an incident where EncryptHub exposed their credentials. SkorikARI's accounts were used to report the vulnerabilities, contributing to Windows security. Evidence linking SkorikARI to EncryptHub includes password files exfiltrated from EncryptHub's system and a GitHub account associated with SkorikARI. EncryptHub has previously attempted to market zero-day vulnerabilities on underground forums and is believed to have affiliations with ransomware groups. The threat actor has executed social engineering campaigns, phishing attacks, and developed a custom infostealer known as Fickle Stealer. They created fictitious social media profiles and websites, such as a fake project management application called GartoriSpace, which installed malicious files on unsuspecting users. EncryptHub has also been implicated in exploiting a Microsoft Management Console vulnerability, CVE-2025-26633.

Tech Optimizer

March 31, 2025

Watch Out for This Info-Stealing Malware on Windows

A new malware strain called CoffeeLoader has been identified, posing a significant risk to gamers by masquerading as a legitimate ASUS utility, specifically the Armoury Crate software. Once it infiltrates a system, it deploys the Rhadamanthys infostealer, which can extract sensitive information such as credentials from web browsers, email clients, cryptocurrency wallets, and password managers. CoffeeLoader evades detection by most security tools by operating on the GPU instead of the CPU and using advanced techniques like call stack spoofing, sleep obfuscation, and exploiting Windows fibers. To protect against CoffeeLoader, users should exercise caution when downloading software, navigate directly to official websites, avoid suspicious links, and adhere to basic cybersecurity practices. If infection is suspected, users should disconnect from the internet, reboot in safe mode, delete temporary files, and check Task Manager for unusual activity. Employing a reliable malware scanner can help identify and eliminate infections.