Winsage
November 25, 2025
Recent observations have identified ClickFix attack variants where cybercriminals use deceptive Windows Update animations on full-screen browser pages to hide malicious code within images. Victims are misled into executing harmful commands through specific key sequences that copy and execute commands via JavaScript. Security researchers have documented these attacks since October, noting the use of LummaC2 and Rhadamanthys information stealers. Attackers utilize steganography to embed malware payloads within PNG images, reconstructing and decrypting them in memory using PowerShell and a .NET assembly called the Stego Loader. A dynamic evasion tactic known as ctrampoline complicates detection by initiating calls to numerous empty functions. The shellcode extracted from the encrypted image can execute various file types directly in memory. Following a law enforcement operation on November 13, the Rhadamanthys variant's payload delivery through fake Windows Update domains ceased, although the domains remain active. Researchers recommend disabling the Windows Run box and monitoring suspicious process chains to mitigate risks.
