Mac Malware Scanners https://discussions.apple.com/message/29938930#29938930

You can also try https://www.malwarebytes.org/antimalware/mac/index.html

Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac=Options) key, and then starting Firefox. A small dialog should appear. Click Start In Safe Mode (not Refresh).

Is the problem still there?

Hi Fred,

thanks, the Malwarebytes Anti-Malware scanner didn't find any threats.

I started Firefox in Safe Mode, and it still does some page loading at the beginning. I have also Refreshed my Firefox installation.

If this is part of Firefox 50, I don't mind. I assume you run Firefox 50 on a Mac, too; does your Firefox do the same after opening?

I use a Win 7, but all Firefox run the same.

Type about:preferences#general<enter> in the address bar. Check your Home Page settings.

Start your Computer in safe mode with networking. Then start Firefox. Try Safe websites. Is the problem still there?

Starting The Computer In Safe Mode;
Free Online Encyclopedia

Thanks; I checked my home page settings, it's set to blank page.

Unfortunately, rebooting into Safe mode, Firefox displays the window as completely white, probably because different graphics drivers were loaded (also white with hardware acceleration turned off). So I couldn't test it this way.

I tried creating a new vanilla profile: The issue persists.

Starting into the Profile Manager, I get this error:

$ /Applications/Firefox.app/Contents/MacOS/firefox-bin -P [warn] kq_init: detected broken kqueue; not using.: Undefined error: 0

Would there be a way to send a DTrace report, or similar, that shows what's happening after opening a new window?

That's above me. I called for more help.

Great, thanks!

I think the problem is cleared up now. Firefox just seems to be contacting their own telemetry server. The HTTP log shows that the server

incoming.telemetry.mozilla.org

is contacted.

Good to hear, well done.

Thanks!