When I move the cursor over to the side bar, another window (sometimes) opens showing a spam site. Why/ how does this happen?
The question says it all. As the cursor moves to the sidebar, a new page/window opens - it can be of the " you have just won £xxxxxxxx , please click on (new ) link" or else some porn site appears- again asking you to click on a link. This is very worrying, it suggess that Firefox has been hacked!
The question says it all. As the cursor moves to the sidebar, a new page/window opens - it can be of the " you have just won £xxxxxxxx , please click on (new ) link" or else some porn site appears- again asking you to click on a link. This is very worrying, it suggess that Firefox has been hacked!
Opaite Mbohovái (3)
Sounds like a malicious extension - cursor proximity to the left side of the browser window opening the sidebar is a feature that was added by an extension, not a standard feature in Firefox.
But how do I get rid of it??
See this support article. https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems