Remove all the history in Firefox (delete all cookies), disable all add-ons and plugins, then restart Firefox. Do not go to any site and wait for about 10-15 min. Go to Options->…->Show cookies. You will see cookie named PREF with google.com domain.
1) Can somebody explain how and why this cookie appears?
2) How to get rid of this?
p.s I don’t have any google desktop application installed. Firefox google search bar is removed too.
This cookie is coming from Google’s safebrowsing api:
This is a known issue in firefox and there is an open ticket here:
https://bugzilla.mozilla.org/show_bug.cgi?id=368255
EDIT To get rid of it, you can turn off the safebrowsing on the security tab (under Options), by un-checking the boxes to Block attacks and forgeries.