If you encounter the same issue, your computer might have been infected by malware. Please read the below removal guide for reference.
What is Us.yhs4.search.yahoo.com?
Us.yhs4.search.yahoo.com has been classified as a browser hijacker. It is usually installed on your computer without your knowledge and approval via other software. Please mind any software you download from the internet. If you need some programs, you can get them from the official sites or reliable clean sites. If you download something from third party websites or suspected links, you may download other unwanted software. So why bother?
