When the Yahoo Search page hijacked the home pages of all three of my browsers, I was quite frustrated to learn that manually changing my home page to get rid of the Yahoo Search tab did not work. Resetting my homepage to Norton Safe Search and removing the Yahoo URL from the home page setting only lasted until the next time I opened a browser or clicked on the home page button. I searched and searched internet forums for this problem and found several threads that looked promising but in the end, none of them worked. Finally, I found a reference to a program named Spigot that was reported to cause this problem but when I looked, I had no such program on my computer. That did, however, give me the clue I needed to find the culprit which turned out to be an installed program named appropriately, "Yahoo Search Set". After uninstalling that program, restarting my computer, and manually resetting the homepage on my browsers, PROBLEM SOLVED! Yeah me!
Also in the process, I learned that this program was piggybacked into my computer as a component of other software that I downloaded. I had already been victimized by failing to read the fine print on the install agreement for downloaded software so I was looking for that but it sneaked around me by loading as an integral component in the software I had downloaded. This means that we now have to click on Custom Install instead of Typical Install or Normal Install to see what components are installing. I cannot point to the culprit software since I had installed 3 different sets of software within the time frame for the hijack.
I am hoping that Norton will classify Yahoo Search Set as malicious since it makes changes to internet browsers without notice or permission!