Look for the "s" for security. Make sure the web sites you are shopping from are secure and have "https" in the URL when you are in their checkout/purchase process.
The "s" ensures security. When you are in the secure section of a web site, you will also see an icon for a locked padlock on your browser, either on the address bar or on the bottom right corner.
Additionally, use the Internet to research online retailers not familiar to you.
Stay current on security software
This means making sure you have the latest virus protection software updates from your security software provider. It's important because the bad guys move around frequently.
Security software companies are working to stay one step ahead of them. If you are updated, you are staying one step ahead, too.
Think before you link
Employ a URL scanning tool to ensure you will be warned if you click on links that lead to infected web pages. The time to find out whether a page is bad is BEFORE you load it into your web browser.
Keep your private information private
When shopping online, create a separate e-mail account that is just for shopping. Use a unique password, different from any other accounts you have.
Your dedicated shopping e-mail account should be in no way affiliated with your personal, everyday e-mail account. Also, keep records of your online shopping - print confirmation pages and e-mail confirmations.
Mix up your passwords
Each shopping account, bank account, credit card account, and e-mail account should have a unique password. Write them down and keep the information in a secure location.
Unique passwords for each account make it tougher for a thief to steal your personal information.
Use common sense
Make sure you use reasonable judgment when buying online and be on the lookout for spoof stores. If an offer seems too good to be true, it probably is.
Take a minute or two to make sure it's not a fake/spoof web site. If the online retailer doesn't provide a physical address, or contact phone numbers, be cautious. Make sure you understand the refund and return policies of any online retailer you are planning to buy from, especially if it's based overseas, just in case something were to go wrong.