Antwort #1 am: 05. August 2016, 12:03:33
without having looked at your files, if you've been hacked or if a virus uploaded from your our your customers's computer, you'll have to
backup the shop for later research (for example on a linux system)
clean every single shop file and the database (if you don't have a backup without malware)
clean all computers that had access (by the way don't forget SD cards and usb sticks)
change database password
change ftp password
if paypal used: change pay api password
check if data for credit cards or banktransfer is still correct
change admin passwords in shop
best practice: change router and wifi password
should be it (did i forget something ?)