Hi Wareham, unwanted redirects and pop-ups are mostly caused by adware infections, nowadays they are very common. Unfortunately antivirus programs sometimes misses such infections. To eliminate adware from your computer first you should check your Control Panel for recently installed suspicious applications. If you recently installed some free software there's a good chance that adware infiltrated your operating system through deceptive freeware installers. When in Control Panel be sure to uninstall all programs that seems out of place. After this procedure reset your Internet browser/s settings (instructions in the references section). If you still encounter hxxp:/ib.adsserve.com pop-ups scan your computer with Malwarebytes Antimalware and AdwCleaner (https://toolslib.net/downloads/viewdownload/1-adwcleaner/).