Read more: https://www.todhost.com/knowledgebase/831/Magento-Website-Security-Tutorial.html

Website security is crucial not just for Magento but also for every other website and every platform. Getting to see one's website being used for phishing, spamming or some other unwholesome activity is one thing so unpleasant a website owner wouldn't want to see. Website security must be taken very seriously.

This post puts you through the details of how you need to secure your Magento website and this involves taking some simple steps.

Change the default username and simple password
Customize the path to your admin panel
Use two-factor authentication
Make a use of secure FTP
Use Trusted Magento Extensions Only
Backup Your Magento Store Regularly
Update your web store on a regular basis
Use Encrypted Connection (SSL/HTTPS)
Create a whitelist of selected IP addresses
Prevent MySQL injection

Read more: https://www.todhost.com/knowledgebase/831/Magento-Website-Security-Tutorial.html