A friend's usb drive is infected by a some malware which is preventing the drive to be formatted or for that case to do anything with any of the files except open them. A scan with defender shows the malware but it is unable to clean it. Even unlocker is unable to delete those files. I have even tried to create a registry entry under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\StorageDevicePolicies named "WriteProtect" & set the value to 0 but in vain.