Viruses are generaly specific to the pc. It's the infection on the pc that is making you see altered content when you visit the site. Use AntiVirus to check and remove infections from your computer. If you can't remove the infections seek professional help.
There are known viruses that will attempt to prevent you acessing AntiVirus sites. It sounds like your infection may try something similar. In this case you may need to download the AntiVirus software onto another pc, save it to removable media then move it to the infected machine for install.
... when I try to access my site at home, it redirects me to some search portal which is full of spams and irrelevant ads.
Before assuming it's a virus - be sure of a couple things.
First, are you using a solid AVG solution, and what is it?
Second, there are conditions that can cause this without malicious intervention. The one I've encountered is your ISP's handling of an invalid request for a site. In short, the ISP can capture the invalid request and instead of a DNS/not found error, feed you a search page/link directory of their own, monetizing invalid URL's. Details of my experience with this [webmasterworld.com], and a second more recent thread [webmasterworld.com].
Although it can be something screwy with your DNS, most often it's a mis-typed URL. I know that's almost insulting, but a missing or extra letter can cause it . . . be sure. :-)