I tried the link you posted, and my anti-virus sounded off;

Category: Intrusion Prevention Date & Time,Risk,Activity,Status,Recommended Action,IPS Alert Name,Default Action,Action Taken,Attacking Computer,Destination Address,Source Address,Traffic Description 12/13/2018 6:42:03 PM,High,An intrusion attempt by reddleops.pro was blocked.,Blocked,No Action Required,Web Attack: Fake Tech Support Domains 2,No Action Required,No Action Required,"reddleops.pro (199.80.54.115, 443)","FRED-PC (172.16.40.148, 62819)",reddleops.pro (199.80.54.115),"TCP, https" Network traffic from reddleops.pro matches the signature of a known attack. The attack was resulted from \DEVICE\HARDDISKVOLUME3\PROGRAM FILES (X86)\MOZILLA FIREFOX 54\FIREFOX.EXE.

I called for more help. Go to your programs folder and remove anything newly installed.

Fred, this is Linux and not the Windows you use.

apeman, what Extensions do you have listed as installed in Firefox even though you say none seem to have a similar name.

I do not use Ubuntu but I would think Ubuntu would not include such an extension with their Firefox package or separate Firefox related packages in package manager.

Firefox from www.mozilla.org/firefox/all certainly does not come with this video download extension.

Do you keep getting tabs or was this a one time action?

You can check the Notifications under "Options/Preferences -> Privacy & Security -> Permissions".

You can see all registered service workers on these pages: about:serviceworkers and about:debugging#workers You can check WebSockets via this page: about:networking#websockets See also serviceworker.txt in the profile folder.

Thank you all for your replies. Cor-el, a couple of those "abouts"- were a little over my head. Hopefully, I can learn how to use those "serviceworkers" and "websockets" things.

  But, yes, I did get those notifications again, but only 2 more times upon starting Firefox.  After that it's not happened any more.   Totally baffles me!  If it re-occurs, I will definitely post again.  Again, thank you all.

-Apeman

apeman said

Upon starting Firefox. (64.0 (64-bit), Ubuntu 16.04), an Addon, which I thought I had -but is not listed in my addons-, "{link to malware removed} , asked to send notifications. I usually deny, but as I mentioned, I thought I had this add-on installed, so I accepted. It then opened these tabs: 1. https://win-big-bonus-here.com/?u=7pfk605&o=e93bvvr&t=1577914_proads_gambling. 2. https://www.amazon.com/s/ref=nb_sb_ss_c_1_20?url=search-alias%3Daps&field- keywords=Genius+surface+pro+3+charger&sprefix=surface+pro+3+charger. I don't have this addon listed, either in my installed addons, or as an available addon. Where did it come from? And how do I get rid of it?