SANS Stormcast Thursday, July 17th, 2025: catbox.moe abuse; Sonicwall Attacks; Rendering Issues

More Free File Sharing Services Abuse The free file-sharing service catbox.moe is abused by malware. While it officially claims not to allow hosting of executables, it only checks extensions and is easily abused https://isc.sans.edu/diary/More%20Free%20File%20Sharing%20Services%20Abuse/32112 Ongoing SonicWall Secure Mobile Access (SMA) Exploitation Campaign using the OVERSTEP Backdoor A group Google identifies as UNC6148 is exploiting the Sonicwall SMA 100 series appliance. The devices are end of life, but even fully patched devices are exploited. Google assumes that these devices are compromised because credentials were leaked during prior attacks. The attacker installs the OVERSTEP backdoor after compromising the device. https://cloud.google.com/blog/topics/threat-intelligence/sonicwall-secure-mobile-access-exploitation-overstep-backdoor Weaponizing Trust in File Rendering Pipelines RenderShock is a comprehensive zero-click attack strategy that targets passive file preview, indexing, and automation behaviours in modern operating systems and enterprise environments. It leverages built-in trust mechanisms and background processing in file systems, email clients, antivirus tools, and graphical user interfaces to deliver payloads without requiring any user interaction. https://www.cyfirma.com/research/rendershock-weaponizing-trust-in-file-rendering-pipelines/