BD picks up worm.generic.508784, file does not exist


We are using Bitdefender Antivirus Plus 2017 to scan USB devices being brought into the building before plugging them into a device on our main network.  Right now I have a flash drive which will come back with the above infection but the associated file is not on the drive.  


 


Infected file is E:\System.exe but no file by that name is on the drive (hidden or otherwise).  No other scanning tool has been able to detect an infection on this drive either.  Am I getting a false positive here or do we have something that's just that good at hiding?