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

SANS Internet Stormcenter Daily Cyber Security Podcast (Stormcast)

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/