malware payloads Archives

Winsage

March 1, 2026

Hackers Abuse Windows File Explorer and WebDAV for Stealthy Malware Delivery

Cybercriminals are exploiting a legacy feature in Windows File Explorer, specifically the WebDAV protocol, to distribute malware and bypass traditional security measures. Despite Microsoft deprecating native WebDAV support in November 2023, it remains active on many systems. Attackers use WebDAV to deceive victims into executing malicious payloads by sending links that connect File Explorer directly to remote servers, avoiding web browsers and their security warnings. They employ methods such as direct linking, URL shortcut files, and LNK shortcut files to deliver exploits. The primary objective of these campaigns, which surged in late 2024, is to deploy Remote Access Trojans (RATs), with 87% of Active Threat Reports involving multiple RATs like XWorm RAT, Async RAT, and DcRAT. These campaigns predominantly target corporate networks in Europe, with many phishing emails written in German and English. Attackers use short-lived WebDAV servers hosted on Cloudflare Tunnel demo accounts to obscure their infrastructure. Security analysts are advised to monitor unusual network activity from Windows Explorer and educate users to verify addresses in File Explorer.

Winsage

December 4, 2025

This Windows Update Pop-Up Is a Scam

Hackers have exploited Windows update screens to deliver malware disguised as a "critical security update," a tactic known as the ClickFix attack. This attack uses social engineering techniques, including fake error messages and CAPTCHA forms, to trick users into executing harmful commands. The scam appears as a pop-up mimicking the standard Windows blue screen but originates from a malicious domain. Users are prompted to paste and execute harmful commands, leading to malware installation. Researchers from Huntress have detailed this attack, noting that malicious code can be embedded within PNG images. Although recent law enforcement actions have reduced the presence of malware payloads on these domains, the threat remains. Users should be cautious of any update screens that do not show a progress indicator or require manual command input, as these are signs of a ClickFix attack. Microsoft releases security updates on the second Tuesday of each month, and users are advised to enable automatic updates and consider disabling the Windows Run box for added security.

Winsage

December 3, 2025

Microsoft mitigates Windows LNK flaw exploited as zero-day

Microsoft has addressed a security vulnerability in Windows tracked as CVE-2025-9491, which allows malicious actors to embed harmful commands in Windows LNK files, requiring user interaction to exploit. Threat actors often distribute these files in ZIP formats to bypass email security. In March 2025, 11 hacking groups, including Evil Corp and Kimsuky, were actively exploiting this vulnerability using various malware payloads. Although Microsoft initially did not consider the issue urgent, it later modified the handling of LNK files in November updates to allow users to view the entire character string in the Target field. However, this change does not eliminate the malicious arguments embedded in the files. ACROS Security has released an unofficial patch that restricts shortcut target strings to 260 characters and alerts users about risks associated with long target strings, covering multiple Windows versions.

Winsage

November 25, 2025

JackFix Uses Fake Windows Update Pop-Ups on Adult Sites to Deliver Multiple Stealers

Cybersecurity experts have identified a new campaign that combines ClickFix tactics with counterfeit adult websites to trick users into executing harmful commands under the guise of a "critical" Windows security update. This campaign uses fake adult sites, including clones of popular platforms, as phishing mechanisms, increasing psychological pressure on victims. ClickFix-style attacks have risen significantly, accounting for 47% of all attacks, according to Microsoft data. The campaign features convincing fake Windows update screens that take over the user's screen and instruct them to execute commands that initiate malware infections. The attack begins when users are redirected to a fake adult site, where they encounter an "urgent security update." The counterfeit Windows Update screen is created using HTML and JavaScript, and it attempts to prevent users from escaping the alert. The initial command executed is an MSHTA payload that retrieves a PowerShell script from a remote server, which is designed to deliver multiple payloads, including various types of malware. The downloaded PowerShell script employs obfuscation techniques and seeks to elevate privileges, potentially allowing attackers to deploy remote access trojans (RATs) that connect to command-and-control servers. The campaign has been linked to other malware execution chains that also utilize ClickFix lures. Security researchers recommend enhancing defenses through employee training and disabling the Windows Run box to mitigate risks associated with these attacks.