Read it here:
It seems Dr.Byte was really scared about this security issues. And some of my clients reported that their site have been affected. Do install this even your site seems to be safe.
The key is “rename admin folder”.
Some Zen Cart users reported that they can’t login to admin after renaming. That’s usually caused by wrong procedures. It’s not a big problem, but if you still can’t figure it out, contact us for help.
For more security issues, please read my later post.