This happened a few minutes ago. I was on Twitter and suddenly all the links there were underlined. That happens on this website as well. I went on Firefox settings to uncheck "Underlined links" box, they are still underlined, and specifically in the Firefox settings website, random letters were underlined when they weren't before, they do not lead to any links though. The underlined links take me to the right location. This doesn't happen in other websites such as Tumblr or Youtube for some reason. I thought it could be a malware, this happened right after I downloaded an app called Rave to my PC. However I searched for info on the app and if it's malicious and I've only heard good things about it. Uninstalled it from my PC just in case and nothing changed. I searched for answers and saw people saying the link stuff could be an adware but the links take me to the right location, I ran Malwarebytes and it didn't detect anything, nor is anything called "Text Enhance" downloaded to my PC. Running another antivirus scan right now. I have no idea what this could be. It's not giving me any serious problems, it's not showing me any suspicious links. It just looks unpleasant and annoying. No idea what this could be. Please help. Added a few example images.