I have been infected by the Servads virus and I have tried a number of different ad blockers to no avail. I have Norton CC cleaner and Spybot on the system.
The link might be helpful for you for step by step instructions
2 Reset your Internet Explorer.
3 Reset homepage.
4 Check the LAN settings of your browser.
Select “Obtain an IP address automatically” and “Obtain DNS server address automatically”.
5 Check your hosts file and remove any malicious entries. reset
6 Check DNS (Domain Name Server) settings
7 Remove servads.com add-on from your web browsers.
boot to safe mode and scan pc witj clamwin, Malwarebytes' Anti-Malware and superantispyware.
Backup your files and use uptodate Ccleaner to remove temp files. Turn off system protection and then scan HD in safe mode with uptodate Malwarebytes or Norton antivirus. Alternitively scan HD with a live CD with uptodate antivirus (available for download from major antivirus software websites). Delete found malware and reboot. Check for activity. If none, turn system protection back on. It might be easier to erase your HD and reload everything.