Try mo po mag download ng Minitool Partition Wizard na application. Free lang po ito. Gamit ang app na yun, click mo ang usb mo at e delete drive mo. Tapos create ka partition, NTFS or FAT32 and click apply. Tapos right-click mo yung partition na ginawa mo, and select wipe partition. On the option, select DoD (3 passes) and click apply. Sana makatulong to sa Usb Virus Issue mo.