What is Ad.yieldmanager.com tracking cookie?
Ad.yieldmanager.com is a tracking cookie that hidden in your Windows system. And it always has been ignored as it is not a virus or a malware.
Once installed, every time you open a new tab within IE, Firefox or Google Chrome, a new tab with and ad from Ad.yieldmanager.com will pop-up.

This infection will also display advertising banners on the webpages that you are visiting, and as you browse Internet, it will show coupons and other deals available on different websites.
The tracking cookies, and especially third-party tracking cookies, are commonly used as ways to compile long-term records of personal browsing histories.