Gettings ads labeled “Ads by Sharp Savings” or text links with a mouse-over saying “Click to Continue > by Sharp Savings”.
Sharp Savings is bundled with free downloads. Here’s how it was disclosed when I found it:
You can remove Sharp Savings from the Windows Control Panel. During the uninstall you need to solve a CAPTCHA.
If the removal fails for some reason, you can remove Sharp Savings with FreeFixer, by selecting the Sharp Savings files (bservice.exe, wd.exe, updater.exe, framworkBHO.dll, etc) as shown in the screenshots. You will also need to manually restore your browser’s proxy settings.