Please Try These Steps...
First, make sure to clean out all your Temporary Internet Files and Cookies (in all browsers), then clean out the "Temp" folders on your computer.. (If using XP, eliminate all files from the "C:\Documents and Settings\Yourusername\Local Settings\Temp" and C:\Windows\Temp folders.
Next, download, install, update, then run full system scans with both free malware removal tools below. (I know that you've already run Malwarebytes but please update and run it again till it finds nothing.):
Hitman Pro 3.5
Next, download TDSSKiller and follow the guide to use the tool:
And when you're done, check your LAN settings in Internet Explorer like this:
Open Internet Explorer and go to Tools-Internet Options-Connection Tab. Click on the LAN settings button. IF there is a check mark next to "Use a proxy server for your LAN", uncheck it. Click OK. Then OK, again.
Hope this helps.