security researchers Archives

Winsage

May 8, 2025

Ransomware hackers target a new Windows security flaw to hit businesses

Several ransomware groups, including RansomEXX and Play, are exploiting a zero-day vulnerability in the Windows Common Log File System to elevate system privileges and deploy malware. This flaw was identified and patched during Microsoft's Patch Tuesday update in April 2024.

Winsage

May 4, 2025

Do Not Open This PDF On A Microsoft Windows PC

Microsoft has warned about the increasing use of PDF attachments in cyberattacks, particularly during the U.S. tax season. Attackers have been using PDFs with embedded links that redirect users to counterfeit pages, such as a fake DocuSign site. TrustWave SpiderLabs has identified a new campaign involving a fake payment SWIFT copy that leads to a malicious PDF containing obfuscated JavaScript, which downloads a script that conceals the RemcosRAT payload using steganography. This technique involves hiding links within images, making them difficult to detect. The latest attacks begin with phishing emails containing malicious PDFs that direct victims to harmful webpages, facilitating the delivery of RemcosRAT, a trojan that allows remote control of compromised systems. Users are advised to be cautious of emails labeled “SWIFT Copy” and to delete suspicious emails immediately.

Winsage

April 30, 2025

Unpatched Windows Shortcut Vulnerability Let Attackers Execute Remote Code

Security researcher Nafiez has discovered a vulnerability in Windows LNK files that allows remote code execution without user interaction. Microsoft has chosen not to address this issue, stating it does not meet their security servicing criteria. The vulnerability exploits specific components of LNK files, enabling attackers to create malicious shortcuts that initiate silent network connections when a user accesses a folder containing them. The exploit involves manipulating the HasArguments flag, EnvironmentVariableDataBlock, and embedding UNC paths. Microsoft defends its inaction by citing the Mark of the Web (MOTW) feature as adequate protection, despite concerns from security experts about its effectiveness. Previous vulnerabilities in LNK files have been addressed by Microsoft, and the availability of proof-of-concept code raises fears of potential exploitation by malicious actors.

Tech Optimizer

April 30, 2025

Avast Antivirus Vulnerability Let Attackers Escalate Privileges

A significant vulnerability, designated as CVE-2025-3500, has been identified in Avast Free Antivirus, allowing attackers to gain elevated system privileges and execute malicious code at the kernel level. The vulnerability has a high CVSS score of 8.8 and was publicly disclosed on April 24, 2025, shortly after a patch was implemented. It originates from inadequate validation of user-supplied data in the aswbidsdriver kernel driver, leading to an integer overflow prior to buffer allocation. Attackers must first execute low-privileged code on the target system to exploit this vulnerability. The flaw affects multiple versions of Avast Free Antivirus, specifically versions ranging from 20.1.2397 to 2016.11.1.2262. A fix was released in version 25.3.9983.922, and users are urged to update their software promptly. Security experts recommend enabling automatic updates and using standard user accounts for daily activities to mitigate risks.

Winsage

April 26, 2025

Windows 11’s Recall AI is now rolling out on Copilot+ PCs

Microsoft has announced the rollout of Windows Recall, a feature for Windows 11 systems with KB5055627 on Copilot+ PCs. Recall uses AI to capture and store visual information from the screen, allowing users to find previously viewed content by describing it in everyday language. Initially unveiled in May 2024, Recall faced privacy concerns, leading Microsoft to pause its rollout for further testing. The feature is now optional and includes enhancements to filter out sensitive information. Recall is part of Windows 11 Build 26100 and will be widely available with the May 2025 Patch Tuesday Update.

Winsage

April 24, 2025

An empty folder in Windows that «cannot be deleted» can permanently block OS updates

The inetpub folder, introduced in the April update of Windows 11 (version 24H2) as part of a fix for the CVE-2025-21204 vulnerability, has raised concerns among security researchers. It can be manipulated to block Windows updates without administrative rights by creating a symbolic link to notepad.exe, which can lead to a rollback of patches and leave the system vulnerable. Microsoft has not yet responded to this issue, and the possibility of a patch to address the new vulnerability is still open.

Winsage

April 24, 2025

Microsoft security patch opens up new security vulnerability

Microsoft's recent update aimed at fixing a security vulnerability (CVE-2025-2104) has unintentionally created an "inetpub" folder on the system drive of Windows operating systems. This folder's creation has raised concerns among IT security researchers, particularly Kevin Beaumont, who warns that it could lead to issues with Windows updates. Users can create junctions that redirect to the "inetpub" folder, potentially causing failures in installing updates and leaving systems vulnerable. Microsoft has stated that the "inetpub" folder should not be deleted and that its presence is part of security enhancements.

Winsage

April 20, 2025

587 Windows Vulnerabilities — A Microsoft Security Record Breaker

Microsoft has reported a record number of 1,360 security vulnerabilities for its products in 2024, marking an 11% increase from 2023. This includes 587 vulnerabilities in Windows (33 classified as critical) and 684 in Windows Server (43 classified as critical). The increase in reported vulnerabilities suggests that security researchers are effectively identifying weaknesses, and Microsoft has invested over a million dollars in bounties to encourage this. The proactive communication and remediation process during Patch Tuesday enhances security, indicating that Microsoft is committed to addressing vulnerabilities rather than being indifferent to user security.

Tech Optimizer

April 16, 2025

Hackers find a way around built-in Windows protections

Windows Defender Application Control (WDAC) is a built-in security feature on Windows PCs that restricts the execution of unauthorized software by allowing only trusted applications. However, hackers have discovered multiple methods to bypass WDAC, exposing systems to malware and cyber threats. Techniques for bypassing WDAC include using Living-off-the-Land Binaries (LOLBins), DLL sideloading, and exploiting misconfigurations in WDAC policies. Attackers can execute unauthorized code without triggering alerts from traditional security solutions, enabling them to install ransomware or create backdoors. Microsoft operates a bug bounty program to address vulnerabilities in WDAC, but some bypass techniques remain unpatched for long periods. Users can mitigate risks by keeping Windows updated, being cautious with software downloads, and using strong antivirus software.

Tech Optimizer

April 15, 2025

New ‘Waiting Thread Hijacking’ Malware Technique Evades Modern Security Measures

Security researchers have developed a new malware process injection technique called "Waiting Thread Hijacking" (WTH), which executes harmful code within legitimate processes while avoiding detection by security measures. This method improves upon traditional Thread Execution Hijacking by using a different sequence of operations that bypasses commonly monitored API calls. WTH involves allocating memory and injecting malicious payloads using standard functions, identifying dormant threads within the target process, acquiring thread context with less suspicious permissions, and overwriting the return address on the stack with the injected shellcode. The technique ensures stability by preserving the original state of the thread and allows it to resume normal operations after executing the malicious code. Additionally, WTH employs an obfuscation technique that distributes its steps across multiple child processes to evade behavioral detection systems. While WTH can avoid many conventional detection triggers, it is not completely immune, as some Endpoint Detection and Response (EDR) solutions can block unauthorized memory writes. Check Point Research has observed that WTH is effective against certain EDRs while others can block it but not older methods, illustrating the variability in EDR capabilities.