https://www.bing.com/search?q=clounfront.net&pc=MOZI&form=MOZSBR '''''Cloudfront.net is a legitimate and safe content delivery network owned by Amazon, however cyber criminals are abusing this CDN to deliver malicious content. This CloudFront.net redirect is usually caused by adware installed on your computer.''''' --------------- You may have ad/mal-ware. Further information can be found in this article; https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-caused-malware?cache=no Run most or all of the listed malware scanners. Each works differently. If one program misses something, another may pick it up.