Google Hijack Viruses – When It Looks Like Google Has a Virus
This is one of the things that will really make it seem like Google has a virus. If you have a Google hijack virus, then your search results will not be from Google anymore. This is actually really simple to diagnose. You just have to search for some things and then carefully examine the results page. Check the address bar. Does it say “www.google.com?" If it doesn't then you've got a Google redirect virus. Another variant is that clicking on search results won't take you to the page that they're supposed to go.
If this is happening, then it is understandable to think that Google has a virus. The problem is on your machine though.
The virus will reroute you to some other place. Ideally you will then click on their special advertisements, which may infect your computer further or just lead to ill-gained profits for the hacker. Do stop before you panic though. If it's another reputable search engine, then you might have just given a toolbar permission to do this. Some legitimate and many shady add-ons and toolbars take these liberties with your system.
In fact, this is a pretty common way to get a malicious Google redirect virus too. Always read the information carefully when you're downloading any program. You may be giving them permission to manage your search results and effectively give them permission to put this virus onto your system. The good news is that these programs try to stay legitimate, so simply uninstalling the toolbar or program might do the trick.
If this isn't the problem or if you can't get rid of the Google redirects, then you're going to have to be a little more aggressive. You need to get a good antivirus program and learn how to remove a Google hijack virus, explained here.