I'll try to put it simple: I restored Firefox because I messed up with fonts and wanted to go back to Default. As expected Firefox created a folder with old stuff and kept my History, Favorites, Downloads and so on. Right after it restored I noticed it kept downloading a lot of .dll and they were all okay according to my antivirus Norton by Symantec. However, right after that Norton started notifying I was being attacked by JS Coinminer Download 6 and it came from my College website that I haven't visited in weeks. Why is that so? How can I get firefox 100% clean? Everytime I open firefox Norton shows up and says it blocked this cryptocurrency mining attack. Further info: This is what Norton says about the malware: JScoinminer is a detection for a JavaScript cryptocurrency miner that runs in web browsers. The javascript coin miner consumes enormous CPU resources, making computer use sluggish. The JavaScript is loaded in the browser when the user visits a web page hosting the JavaScript. The JavaScript runs as long as the user stays on the web page. And Norton notifies me that the intrusion attempt comes from \DEVICE\HARDDISKVOLUME3\PROGRAM FILES (X86)\MOZILLA FIREFOX\FIREFOX.EXE.