Malware detection - Norton, Mcafee, Etc.

A visitor to my site informed me today that it is being blocked by security software such as Norton and Mcafee for "malicious content". After reading about this I double checked that I have the SSL enabled and my site is showing as secure on chrome. I also discovered that it may be due to mixed content because I have added custom CSS code to my site for various design elements. Is there a way to check the site code and remove anything that may be causing this security flag? I already submitted appeals to both software companies but not sure if there is something I can do on my end to prevent this from being an issue. 

@tuanphan any advice on this one? 

Hi,

What is your site url?

I am having the same problem. I have tried SS Help, who have been no help at all. I'm now looking into local and online services to help clear the blocks and/or any potential malware.

Have you found any solutions?