There is a new sort of Google redirect virus, the 404 nginx virus. It displays ads, steals data, passwords and causes connection problems or displays a 404 nginx when you open Google. To solve this download the fixit (made by Microsoft)https://support.microsoft.com/kb/972034#FixItForMeAlways
Or do it manually: https://deletemalware.blogspot.nl/2011/08/remove-404-not-found-nginx-uninstall.html
When you are done use malwarebytes to completely remove it. Hope I helped 