I don't understand

Before I used Google Chrome as my browser I was using Firefox. But because I heard it that it's more faster so I change it. I really don't have any problem at it from the beginning until later. You see, I am into many meme's and of course I have to visit many bloggers all over the world. Then one time I came to this blog site and a pop out came out, it say's the website has a malware, so I stopped visiting that site which I really don't want to from the very beginning. Then I later noticed that even if I go search some sites a noticed popped out, I now then wonder why it is happening. Then two days ago, I was just surprised when I open my blog site it says I can't go to this site because it has a malware, I was very surprised about it. I run my AVG protection everything was fine. So I change my  browser back to Firefox, then try to visit my blogs everything was fine. Then I tried to visit bloggers site they are all fine. I don't understand this, is this only the thing for Google Chrome browser? I even search this and some even had a popped out telling that the site has malware even to the pages of BBC or government pages, hmmm.  So now I am back to Firefox browser. ^_^