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.

hello msugar,

FireFox does not have that file as part of its installation files.

So your system sounds like its infected and FireFox is being used as part of that infection.

Do a google search on the following to see what others are saying about this:

" cs9.wac.phicdn.net malwarebytes "