Where can I read manga online without getting viruses?

Lately, I've been getting a lot of viruses on my computer. I've pinpointed mangafox.com and onemanga.com as a couple of sources; it's when I would visit these sites that I would get messages like "your computer is infected! would you like to activate your anti-virus software now?", and then have to deal with the annoying viruses that pretend to be anti-virus software. I have my own anti-virus software but it still does that sometimes. I want to read different mangas without the frustration; does anyone else have a problem like this?