YellowKey BitLocker Bypass - FsTx Folder Staging
Detects the creation or modification of the 'FsTx' directory within 'System Volume Information' on any volume, which is a staging step required by the YellowKey BitLocker bypass (Windows 11, Server 2022/2025). The attacker copies the FsTx folder to either a USB stick's System Volume Information directory OR the target machine's EFI System Partition, then reboots into WinRE while holding CTRL to trigger a shell with unrestricted access to the BitLocker-protected volume. The FsTx folder name has no legitimate use; modifications to System Volume Information by non-system processes are inherently suspicious.
Cortex XDR
