C&C Callback Address [Malware !!]
Im used Firefox (v91.0.2 32bit) on Windows 10 Pro and anti-virus (Trend micro) alert has malware on FF to open website. im open https://www.cloudflare.com and then my use Google Chrome to open https://www.cloudflare.com and the anti-virus not alert warning. The Admin talk to me firefox has malware.!!!! (sorry for bad Eng.)
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 free to use malware scanners. Each works differently. If one program misses something, another may pick it up.