32 on use ATM, Windows OS but it varies on 7, 8, 10 (it was a mess when i first arrived, not too long) all of them are 64-bit, it creates shortcuts of every file and folder inside the flashdrive and hides the real files in a hidden folder, the students click on the quick-access files, they are rather naive and uninformed about these things, so when they click on them, the virus creates a script as a process and sets itselt on startup boots, any flashdrive that you put in that is not infected, will repeat the method of creating the quick-access files.
The computer were using the ESET NOD32 antivirus but the main office hasn't renewed the license yet so i have to look for alternatives before all the computers become infected
@David H. Lipman I can't lock the use of the flashdrives because the students use them to take their work home, the issue mostly happens during the CompSci classes.