If you did not format your flash drive, then check whether the files are not in hidden mode. Follow the following steps.

• Click here download the file “AutorunExterminator“

 

• Extract it –> Double-click on “AutorunExterminator” –> Plug your flash drive now.
  This will remove the autorun.inf files from your flash drive and also from your drives.

 

• Click on “Windows Key + R ”  type cmd and click on OK

  .

• Here I assume your flash drive letter as F: Enter this command.attrib -h -r -s /s /d f:\*.*

  

  You can copy the above command –> Right-click in the Command Prompt and paste it.

  Note : Don’t forget to replace the letter F with your flash drive letter. Now press “Enter”.
• After that, download the Malwarebytes’ Anti-Malware from the below link http://en.kioskea.net/download/download-105-malwarebytes-anti-malware
• Update it –> Perform “Full Scan”