SANS Stormcast Tuesday, June 3rd, 2025: Windows SSH C2; Google Removes CAs from trusted list; MSFT issues Emergency Patch to fix Crash issue; Qualcom Adreno GPU 0-day

Simple SSH Backdoor Xavier came across a simple SSH backdoor taking advantage of the ssh client preinstalled on recent Windows systems. The backdoor is implemented via an SSH configuration file that instructs the SSH client to connect to a remote system and forward a shell on a random port. This will make the shell accessible to anybody able to connect to the C2 host. https://isc.sans.edu/diary/Simple%20SSH%20Backdoor/32000 Google Chrome to Distrust CAs Google Chrome will remove the Chunghwa Telecom and Netlock certificate authorities from its list of trusted CAs. Any certificates issued after July 31st will not be trusted. Certificates issued before the deadline will be trusted until they expire. https://security.googleblog.com/2025/05/sustaining-digital-certificate-security-chrome-root-store-changes.html Microsoft Emergency Update to Fix Crashes Caused by May Patch Microsoft released an emergency update for a bug caused by one of the patches released in May. Due to the bug, systems may not restart after the patch is applied. This affects, first of all, virtual systems running in Azure and HyperV but apparently has also affected some physical systems. https://learn.microsoft.com/en-us/windows/release-health/status-windows-11-23h2#kb5058405-might-fail-to-install-with-recovery-error-0xc0000098-in-acpi-sys Qualcomm Adreno Graphics Processing Unit Patch (Exploited!) Qualcomm released an update for the driver for its Adreno GPU. The patched vulnerability is already being exploited against Android devices. https://docs.qualcomm.com/product/publicresources/securitybulletin/june-2025-bulletin.html